likely to go back to registers for most temporaries.
most tests in lib pass. these fail:
datafmt
fmt
go/scanner
log
reflect
strconv
template
R=ken
OCL=29896
CL=29898
* floating point -> integer conversions.
x86 defines that overflow/underflow
results in 1<<15, 1<<31, 1<<63 for
int16, int32, int64. when building the
unsigned conversions out of the native signed
ones, 8g turns overflow/underflow into zero.
the spec does not say what should happen.
* many tiny bug fixes. can run a large number
of files from go/test now, and can fmt.Printf.
* struggling with byte register allocation
and float32 computation.
R=ken
OCL=29642
CL=29811
