A struct with a single field was considered as equivalent to the
field type, which is incorrect is the field is blank.
Fields with padding could make the compiler think some
types are comparable when they are not.
Fixes#5698.
R=rsc, golang-dev, daniel.morsing, bradfitz, gri, r
CC=golang-dev
https://golang.org/cl/10271046
Very few of the compiler regression tests include a comment
saying waht they do. Many are obvious, some are anything but.
I've started with a-c in the top directory. More will follow once
we agree on the approach, correctness, and thoroughness here.
zerodivide.go sneaked in too.
R=rsc, r
CC=golang-dev
https://golang.org/cl/5656100
I haven't looked at the source, but the gc compiler appears to
omit "not used" errors when there is an error in the
initializer. This is harder to do in gccgo, and frankly I
think the "not used" error is still useful even if the
initializer has a problem. This CL tweaks some tests to avoid
the error, which is not the point of these tests in any case.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5561059
