The test case of issue 4585 was not passing due to
miscalculation of memequal args, and the previous fix
does not handle padding at the end of a struct.
Handling of padding at end of structs also fixes the case
of [n]T where T is such a padded struct.
Fixes#4585.
(again)
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7133059
runoutput styles tests generally consume a lot of memory. On arm platforms rotate?.go consume around 200mb each to compile, and as tests are sorted alphabetically, they all tend to run at once.
This change limits the number of runoutput jobs to 2 on arm platforms.
R=minux.ma, remyoudompheng, bradfitz, lucio.dere
CC=golang-dev
https://golang.org/cl/7099047
The linker split PKGDEF into (prefix, name, def) pairs,
and defines def to begin after a space following the identifier.
This is totally wrong for the following export data:
func "".FunctionName()
var SomethingCompletelyUnrelated int
The linker would parse
name=`"".FunctionName()\n\tvar`
def=`SomethingCompletelyUnrelated int`
since there is no space after FunctionName.
R=minux.ma, rsc
CC=golang-dev
https://golang.org/cl/7068051
A constant node of type uintptr with a nil literal could
happen in two cases: []int(nil)[1:] and
uintptr(unsafe.Pointer(nil)).
Fixes#4614.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7059043
Unnamed types like structs with embedded fields can have methods.
These methods are generated on-the-fly by the compiler and
it may happen for identical types in different packages.
The linker must accept these multiple definitions.
Fixes#4590.
R=golang-dev, rsc
CC=golang-dev, remy
https://golang.org/cl/7030051
Before this CL, defining the variable worked fine, but then when
the implicit package-level init func was created, that caused a
name collision and a confusing error about the redeclaration.
Also add a test for issue 3705 (func init() needs body).
Fixes#4517.
R=ken2
CC=golang-dev
https://golang.org/cl/7008045
Ordinary variable load was assumed to be not worth saving,
but not if one of the function calls later might change
its value.
Fixes#4313.
R=ken2
CC=golang-dev
https://golang.org/cl/6997047
The patch makes the compile user an ordinary package-local
symbol for the name of embedded fields of builtin type.
This is incompatible with the fix delivered for issue 2687
(revision 3c060add43fb) but fixes it in a different way, because
the explicit symbol on the field makes the typechecker able to
find it in lookdot.
Fixes#3552.
R=lvd, rsc, daniel.morsing
CC=golang-dev
https://golang.org/cl/6866047
The typechecking code was doing an extra, unnecessary
indirection.
Fixes#4458.
R=golang-dev, daniel.morsing, rsc
CC=golang-dev
https://golang.org/cl/6998051
A fatal error used to happen when escassign-ing a multiple
function return to a single node. However, the situation
naturally appears when using "go f(g())" or "defer f(g())",
because g() is escassign-ed to sink.
Fixes#4529.
R=golang-dev, lvd, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/6920060
I just committed a patch to gccgo that notices that float was
never defined, causing an additional unmatched error message.
Rename the type to avoid that message.
R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/6947049
This check for BADWIDTH might happen while in defercheckwidth, making it raise errors for non-erroneous situations.
Fixes#4495.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6927043
Used to say:
issue4251.go:12: inverted slice range
issue4251.go:12: constant -1 overflows uint64
issue4251.go:16: inverted slice range
issue4251.go:16: constant -1 overflows uint64
issue4251.go:20: inverted slice range
issue4251.go:20: constant -1 overflows uint64
With this patch, only gives the "inverted slice range" errors.
R=golang-dev, daniel.morsing
CC=golang-dev
https://golang.org/cl/6871058
Fixes#4396.
For fixed arrays larger than the unmapped page, agenr would general a nil check by loading the first word of the array. However there is no requirement for the first element of a byte array to be word aligned, so this check causes a trap on ARMv5 hardware (ARMv6 since relaxed that restriction, but it probably still comes at a cost).
Switching the check to MOVB ensures alignment is not an issue. This check is only invoked in a few places in the code where large fixed arrays are embedded into structs, compress/lzw is the biggest offender, and switching to MOVB has no observable performance penalty.
Thanks to Rémy and Daniel Morsing for helping me debug this on IRC last night.
R=remyoudompheng, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/6854063
The current spec says that when calling make, if both len and
cap are constant, it is an error if len > cap. The gc
compiler does not yet implement that, but when it does this
will need to change. Changing it now for the benefit of
gccgo.
R=gri
CC=golang-dev
https://golang.org/cl/6867064
The compiler was confused when inlining a T.Method(f()) call
where f returns multiple values: support for this was marked
as TODO.
Variadic calls are not supported but are not inlined either.
Add a test preventively for that case.
Fixes#4167.
R=golang-dev, rsc, lvd
CC=golang-dev
https://golang.org/cl/6871043
Bools from comparisons can be assigned to all bool types, but this idealness would propagate through logical operators when the result should have been lowered to a non-ideal form.
Fixes#3924.
R=golang-dev, remyoudompheng, r, rsc, mtj
CC=golang-dev
https://golang.org/cl/6855061
The stack overflow checker in the linker uses the spadj field
to determine whether stack space will be large enough or not.
When spadj=0, the checker treats the function as a nosplit
and emits an error although the program is correct.
Also enable the stack checker in 8l.
Fixes#4316.
R=rsc, golang-dev
CC=golang-dev
https://golang.org/cl/6855088
The patch adds more cases to agenr to allocate registers later,
and makes 6g generate addresses for sgen in something else than
SI and DI. It avoids a complex save/restore sequence that
amounts to allocate a register before descending in subtrees.
Fixes#4207.
R=golang-dev, dave, rsc
CC=golang-dev
https://golang.org/cl/6817080
When exporting a body containing
x, ok := v.(Type)
the definition for Type was not being included, so when the body
was actually used, it would cause an "unknown type" compiler error.
Fixes#4370.
R=ken2
CC=golang-dev
https://golang.org/cl/6827064
Running this test via "bash run" uncovered three different
bugs (4344, 4348, 4353). We need to run it by default.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6832043
The code assumed that the only choices were EscNone, EscScope, and EscHeap,
so that it makes sense to set EscScope only if the current setting is EscNone.
Now that we have the many variants of EscReturn, this logic is false, and it was
causing important EscScopes to be ignored in favor of EscReturn.
Fixes#4360.
R=ken2
CC=golang-dev, lvd
https://golang.org/cl/6816103
The old code worked with gc, I assume because the linker
unified identical strings, but it failed with gccgo.
R=rsc
CC=gobot, golang-dev
https://golang.org/cl/6826063
Avoids problems with local declarations shadowing other names.
We write a more explicit form than the incoming program, so there
may be additional type annotations. For example:
int := "hello"
j := 2
would normally turn into
var int string = "hello"
var j int = 2
but the int variable shadows the int type in the second line.
This CL marks all local variables with a per-function sequence number,
so that this would instead be:
var int·1 string = "hello"
var j·2 int = 2
Fixes#4326.
R=ken2
CC=golang-dev
https://golang.org/cl/6816100
The compiler now gives an error for out of bounds constant
indexes for arrays, and for negative constant indexes for both
arrays and slices.
With this change the index.go test passes if CLs 6815085,
6815088, and 6812089 are committed.
R=golang-dev, remyoudompheng, rsc
CC=golang-dev
https://golang.org/cl/6810085
Compiling expressions like:
s[s[s[s[s[s[s[s[s[s[s[s[i]]]]]]]]]]]]
make 5g and 6g run out of registers. Such expressions can arise
if a slice is used to represent a permutation and the user wants
to iterate it.
This is due to the usual problem of allocating registers before
going down the expression tree, instead of allocating them in a
postfix way.
The functions cgenr and agenr (that generate a value to a newly
allocated register instead of an existing location), are either
introduced or modified when they already existed to allocate
the new register as late as possible, and sudoaddable is disabled
for OINDEX nodes so that igen/agenr is used instead.
Update #4207.
R=dave, daniel.morsing, rsc
CC=golang-dev
https://golang.org/cl/6733055
When local declarations needed unexported types, these could
be missing in the export data.
Fixes build with -gcflags -lll, except for exp/gotype.
R=golang-dev, rsc, lvd
CC=golang-dev
https://golang.org/cl/6813067
I fixed a bug in gccgo that was causing it to only give an
error for the first package that was imported and not used.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6813058
includes step 0: synthesize outparams, from 6600044
includes step 1,2: give outparams loopdepth 0 and verify unchanged results
generate esc:$mask tags, but still tie to sink if a param has mask != 0
from 6610054
adds final steps:
- have esccall generate n->escretval, a list of nodes the function results flow to
- use these in esccall and ORETURN/OAS2FUNC/and f(g())
- only tie parameters to sink if tag is absent, otherwise according to mask, tie them to escretval
R=rsc, bradfitz
CC=dave, gobot, golang-dev, iant, rsc
https://golang.org/cl/6741044
Someone new to the language may not know the connection between ints and arrays, which was the only thing that the previous error told you anything about.
Fixes#4256.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6739048
Since this patch changes the way complex literals are written
in export data, there are a few other glitches.
Fixes#4159.
R=golang-dev, rsc
CC=golang-dev, remy
https://golang.org/cl/6674047
This patch is enough to fix compilation of
exp/types tests but only passes a stripped down
version of the appripriate torture test.
Update #4207.
R=dave, nigeltao, rsc, golang-dev
CC=golang-dev
https://golang.org/cl/6621061
The other tests either need a complex procedure
or are architecture- or OS-dependent.
Update #4139.
R=golang-dev, daniel.morsing, iant
CC=golang-dev
https://golang.org/cl/6618062
testlib will complain about any unmatched errors left in errorchecks while run.go will not.
Fixes#4141.
R=golang-dev, minux.ma, remyoudompheng, rsc
CC=golang-dev
https://golang.org/cl/6614060
If we're benchmarking 8g, use gcc -m32.
If we're benchmarking 6g, use gcc -m64.
R=golang-dev, bradfitz, minux.ma, remyoudompheng
CC=golang-dev
https://golang.org/cl/6625061
The nil dereference in the next few lines doesn't seem
to cause a segmentation fault on Unix, but does seem
to halt the Go compiler.
The following is a test case:
>>>
package main
func mine(int b) int {
return b + 2
}
func main() {
mine()
c = mine()
}
<<<
Without this change only the following is caught:
typecheck.go:3: undefined: b
typecheck.go:4: undefined: b
with it, we catch all the errors:
typecheck.go:3: undefined: b
typecheck.go:4: undefined: b
typecheck.go:10: undefined: c
typecheck.go:10: cannot assign to c .
R=rsc, minux.ma
CC=golang-dev
https://golang.org/cl/6542060
rundir will compile each file in the directory in lexicographic order, link the last file as the main package and run the resulting program. rundircmpout is an related command, that will compare the output of the program to an corresponding .out file
errorcheckdir will compile each file in a directory in lexicographic order, running errorcheck on each file as it compiles. All compilations are assumed to be successful except for the last file. However, If a -0 flag is present on the command, the last compilation will also be assumed successful
This CL also includes a small refactoring of run.go. It was getting unwieldy and the meaning of the run commands was hidden behind argument line formatting.
Fixes#4058.
R=rsc, minux.ma, remyoudompheng, iant
CC=golang-dev
https://golang.org/cl/6554071
Also mention that ignoring second blank identifier of range is required by the spec in the code.
Fixes#4173.
R=daniel.morsing, remyoudompheng, r
CC=golang-dev
https://golang.org/cl/6594043
const1.go:31:12: error: integer constant overflow
const1.go:31:12: error: integer constant overflow
const1.go:33:12: error: integer constant overflow
const1.go:33:12: error: integer constant overflow
const1.go:34:14: error: integer constant overflow
const1.go:35:17: error: integer constant overflow
const1.go:35:17: error: integer constant overflow
const1.go:35:17: error: integer constant overflow
const1.go:35:17: error: integer constant overflow
const1.go:35:17: error: integer constant overflow
const1.go:36:19: error: integer constant overflow
const1.go:37:15: error: integer constant overflow
const1.go:37:15: error: integer constant overflow
const1.go:37:24: error: integer constant overflow
const1.go:37:15: error: integer constant overflow
const1.go:37:15: error: integer constant overflow
const1.go:37:15: error: integer constant overflow
const1.go:37:24: error: integer constant overflow
const1.go:37:15: error: integer constant overflow
const1.go:38:12: error: integer constant overflow
const1.go:38:12: error: integer constant overflow
const1.go:38:12: error: integer constant overflow
const1.go:38:12: error: integer constant overflow
const1.go:41:20: error: integer constant overflow
const1.go:41:20: error: integer constant overflow
const1.go:42:20: error: integer constant overflow
const1.go:42:20: error: integer constant overflow
const1.go:44:28: error: integer constant overflow
const1.go:44:28: error: integer constant overflow
const1.go:45:14: error: integer constant overflow
const1.go:49:14: error: integer constant overflow
const1.go:50:14: error: integer constant overflow
const1.go:51:14: error: integer constant overflow
const1.go:54:23: error: integer constant overflow
const1.go:54:23: error: integer constant overflow
const1.go:54:23: error: integer constant overflow
const1.go:54:23: error: integer constant overflow
const1.go:56:14: error: integer constant overflow
const1.go:57:24: error: integer constant overflow
const1.go:57:24: error: integer constant overflow
const1.go:58:24: error: integer constant overflow
const1.go:58:24: error: integer constant overflow
const1.go:59:22: error: integer constant overflow
const1.go:59:22: error: integer constant overflow
const1.go:61:24: error: integer constant overflow
const1.go:62:20: error: division by zero
const1.go:65:19: error: floating point constant overflow
const1.go:65:19: error: floating point constant overflow
const1.go:66:28: error: floating point constant overflow
const1.go:66:28: error: floating point constant overflow
const1.go:67:19: error: floating point constant overflow
const1.go:67:19: error: floating point constant overflow
const1.go:68:19: error: division by zero
const1.go:33:14: error: integer constant overflow
const1.go:35:19: error: integer constant overflow
const1.go:42:22: error: integer constant overflow
const1.go:53:17: error: integer constant overflow
const1.go:55:14: error: integer constant overflow
const1.go:59:24: error: integer constant overflow
const1.go:69:20: error: expected integer type
const1.go:75:4: error: argument 1 has incompatible type (cannot use type int8 as type int)
const1.go:76:4: error: argument 1 has incompatible type (cannot use type int8 as type int)
const1.go:77:4: error: argument 1 has incompatible type (cannot use type uint8 as type int)
const1.go:79:4: error: argument 1 has incompatible type (cannot use type float32 as type int)
const1.go:80:4: error: argument 1 has incompatible type (cannot use type float64 as type int)
const1.go:81:4: error: floating point constant truncated to integer
const1.go:83:4: error: argument 1 has incompatible type (cannot use type float64 as type int)
const1.go:84:4: error: argument 1 has incompatible type (cannot use type string as type int)
const1.go:85:4: error: argument 1 has incompatible type (cannot use type bool as type int)
const1.go:88:7: error: const initializer cannot be nil
const2.go:14:8: error: expected ‘=’
const5.go:27:7: error: expression is not constant
const5.go:28:7: error: expression is not constant
const5.go:30:7: error: expression is not constant
const5.go:31:7: error: expression is not constant
ddd1.go:57:23: error: invalid use of ‘...’ in type conversion
ddd1.go:59:6: error: invalid use of ‘...’ in type conversion
ddd1.go:60:12: error: use of ‘[...]’ outside of array literal
ddd1.go:21:15: error: argument 1 has incompatible type
ddd1.go:22:10: error: argument 1 has incompatible type
ddd1.go:30:6: error: invalid use of ‘...’ with non-slice
ddd1.go:30:6: error: invalid use of ‘...’ with non-slice
ddd1.go:46:2: error: invalid use of %<...%> with builtin function
ddd1.go:47:2: error: invalid use of %<...%> with builtin function
ddd1.go:49:2: error: invalid use of %<...%> with builtin function
ddd1.go:50:6: error: invalid use of %<...%> with builtin function
ddd1.go:51:6: error: invalid use of %<...%> with builtin function
ddd1.go:53:6: error: invalid use of %<...%> with builtin function
ddd1.go:58:13: error: invalid use of %<...%> with builtin function
ddd1.go:20:10: error: floating point constant truncated to integer
ddd1.go:32:6: error: invalid use of ‘...’ calling non-variadic function
declbad.go:20:3: error: variables redeclared but no variable is new
declbad.go:38:3: error: variables redeclared but no variable is new
declbad.go:44:3: error: variables redeclared but no variable is new
declbad.go:51:3: error: variables redeclared but no variable is new
declbad.go:57:3: error: variables redeclared but no variable is new
declbad.go:63:3: error: variables redeclared but no variable is new
declbad.go:26:3: error: incompatible types in assignment (cannot use type float32 as type int)
declbad.go:32:3: error: incompatible types in assignment (cannot use type int as type float32)
declbad.go:44:3: error: incompatible types in assignment (different number of results)
fixedbugs/bug223.go:21:5: error: initialization expression for ‘m’ depends upon itself
fixedbugs/bug412.go:10:2: error: duplicate field name ‘x’
fixedbugs/bug413.go:11:5: error: initialization expression for ‘i’ depends upon itself
fixedbugs/bug416.go:13:1: error: method ‘X’ redeclares struct field name
fixedbugs/bug435.go:15:49: error: missing ‘)’
fixedbugs/bug435.go:15:2: error: reference to undefined name ‘bar’
fixedbugs/bug451.go:9:9: error: expected package
typeswitch3.go:39:9: error: no new variables on left side of ‘:=’
typeswitch3.go:24:2: error: impossible type switch case (type has no methods)
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6560063
The assembly offsets were converted mechanically using
code.google.com/p/rsc/cmd/asmlint. The instruction
changes were done by hand.
Fixes#2188.
R=iant, r, bradfitz, remyoudompheng
CC=golang-dev
https://golang.org/cl/6550058
Was not handling &x.y[0] and &x.y.z correctly where
y is an array or struct-valued field (not a pointer).
R=ken2
CC=golang-dev
https://golang.org/cl/6551059
Can tell this doesn't get run very often, but it is still important
for when you've broken everything else.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6547065
Today, if run.go doesn't understand a test header line it just ignores
the test, making it too easy to write or edit tests that are not actually
being run.
- expand errorcheck to accept flags, so that bounds.go and escape*.go can run.
- create a whitelist of skippable tests in run.go; skipping others is an error.
- mark all skipped tests at top of file.
Update #4139.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6549054
Revision 63f7abcae015 introduced a bug caused by
code assuming registers started at X5, not X0.
Fixes#4138.
R=rsc
CC=golang-dev, remy
https://golang.org/cl/6558043
use a function to get stdout and stderr, instead of depending
on a specific libc implementation.
also make test/run.go replace \r\n by \n before comparing
output.
Fixes#2121.
Part of issue 1741.
R=alex.brainman, rsc, r, remyoudompheng
CC=golang-dev
https://golang.org/cl/5847068
In switches without an expression, the compiler would not convert the implicit true to an interface, causing codegen errors.
Fixes#3980.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6497147
Broke tests on 386.
««« original CL description
6l/8l: emit correct opcodes to F(SUB|DIV)R?D.
When the destination was not F0, 6l and 8l swapped FSUBD/FSUBRD and
FDIVD/FDIVRD.
R=golang-dev, dave, rsc
CC=golang-dev
https://golang.org/cl/6498092
»»»
R=golang-dev
CC=golang-dev
https://golang.org/cl/6492100
Accomplished by synchronizing the formatting of conversion errors between typecheck.c and subr.c
Fixes#3984.
R=golang-dev, remyoudompheng, rsc
CC=golang-dev
https://golang.org/cl/6500064
This fixes a spurious 'invalid recursive type' error, and stops the compiler from emitting errors on uses of the invalid type.
Fixes#3766.
R=golang-dev, dave, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/6443100
This is required by the spec to produce the replacement char.
The fix lies in lib9's rune code.
R=golang-dev, nigeltao, rsc
CC=golang-dev
https://golang.org/cl/6443109
CVTSS2SQ's rounding mode is controlled by the RC field of MXCSR;
as we specifically need truncate semantic, we should use CVTTSS2SQ.
Fixes#3804.
R=rsc, r
CC=golang-dev
https://golang.org/cl/6352079
Surrogate halves are part of UTF-16 and should never appear in UTF-8.
(The rune that two combined halves represent in UTF-16 should
be encoded directly.)
Encoding: encode as RuneError.
Decoding: convert to RuneError, consume one byte.
This requires changing:
package unicode/utf8
runtime for range over string
Also added utf8.ValidRune and fixed bug in utf.RuneLen.
Fixes#3927.
R=golang-dev, rsc, bsiegert
CC=golang-dev
https://golang.org/cl/6458099
Enhances test/run.go to support testing other directories
Will enable stdio tests on Windows in a follow-up CL.
R=golang-dev, alex.brainman, rsc
CC=golang-dev
https://golang.org/cl/6220049
The compiler is incorrectly rejecting switches on arrays of
comparable types. It also doesn't catch incomparable structs
when typechecking the switch, leading to unreadable errors
during typechecking of the generated code.
Fixes#3894.
R=rsc
CC=gobot, golang-dev, r, remy
https://golang.org/cl/6442074
we can't import "./bug0" on windows, as it will trigger
"import path contains invalid character ':'" error.
instead, we pass "-D." and "-I." to gc to override this
behavior. this idea is due to remyoudompheng.
R=golang-dev, r, alex.brainman, remyoudompheng
CC=golang-dev
https://golang.org/cl/6441074
The receive operator was given incorrect precedence
resulting in incorrect deletion of parentheses.
Fixes#3843.
R=rsc
CC=golang-dev, remy
https://golang.org/cl/6442049
The compiledir pattern compiles all files xxx.dir/*.go
in lexicographic order (which is assumed to coincide with
the topological order of dependencies).
R=rsc
CC=golang-dev, remy
https://golang.org/cl/6440048
They were previously ignored when deciding order and
detecting dependency loops.
Fixes#3824.
R=rsc, golang-dev
CC=golang-dev, remy
https://golang.org/cl/6455055
There may be further savings if convT2I can avoid the function call
if the cache is good and T is uintptr-shaped, a la convT2E, but that
will be a follow-up CL.
src/pkg/runtime:
benchmark old ns/op new ns/op delta
BenchmarkConvT2ISmall 43 15 -64.01%
BenchmarkConvT2IUintptr 45 14 -67.48%
BenchmarkConvT2ILarge 130 101 -22.31%
test/bench/go1:
benchmark old ns/op new ns/op delta
BenchmarkBinaryTree17 8588997000 8499058000 -1.05%
BenchmarkFannkuch11 5300392000 5358093000 +1.09%
BenchmarkGobDecode 30295580 31040190 +2.46%
BenchmarkGobEncode 18102070 17675650 -2.36%
BenchmarkGzip 774191400 771591400 -0.34%
BenchmarkGunzip 245915100 247464100 +0.63%
BenchmarkJSONEncode 123577000 121423050 -1.74%
BenchmarkJSONDecode 451969800 596256200 +31.92%
BenchmarkMandelbrot200 10060050 10072880 +0.13%
BenchmarkParse 10989840 11037710 +0.44%
BenchmarkRevcomp 1782666000 1716864000 -3.69%
BenchmarkTemplate 798286600 723234400 -9.40%
R=rsc, bradfitz, go.peter.90, daniel.morsing, dave, uriel
CC=golang-dev
https://golang.org/cl/6337058
otherwise it fails spuriously with "newfunc allocated unexpectedly" message
when run with GOMAXPROCS>1 (other goroutine allocates).
R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/6347056
-lm must come after the source file, versions of gcc insist this strict order.
On standard compliant systems, we no longer need malloc.h for malloc.
Use pkg-config(1) to get correct glib cflags and libs.
Fix compiler warning in threadring.c and k-nucleotide.c.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6198076
CL 4313064 fixed its test case but did not address a
general enough problem:
type T1 struct { F *T2 }
type T2 T1
type T3 T2
could still end up copying the definition of T1 for T2
before T1 was done being evaluated, or T3 before T2
was done.
In order to propagate the updates correctly,
record a copy of an incomplete type for re-execution
once the type is completed. Roll back CL 4313064.
Fixes#3709.
R=ken2
CC=golang-dev, lstoakes
https://golang.org/cl/6301059
