cmd/6g: fix internal error with SSE registers.

Revision 63f7abcae015 introduced a bug caused by
code assuming registers started at X5, not X0.

Fixes issue 4138.

R=rsc
CC=golang-dev, remy
http://codereview.appspot.com/6558043
test: expand run.go's errorcheck, make clear which bugs run

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 issue 4139.

R=golang-dev, bradfitz
CC=golang-dev
http://codereview.appspot.com/6549054
doc: Remove obsolete references to weekly releases.

This was misleading and often confusing for new users.

Leaving the actual weekly release history page for historical reference.

R=golang-dev, rsc, adg
CC=golang-dev
http://codereview.appspot.com/6555053

Committer: Andrew Gerrand <adg@golang.org>
pkg/go/ast: Avoid doing zero-length writes to the fd.

After each line, ast.Print would do a zero-length write,
which would hit the boundary condition on Plan 9 when
reading over pipes (since message boundaries are
preserved). This change makes sure we only do positive-
length writes.

R=rsc, rminnich, dave, r
CC=golang-dev
http://codereview.appspot.com/6558046

Committer: Rob Pike <r@golang.org>
net/http: use r.Body.Close to close connection during TestServeFileFromCWD

Fixes issue 3917.

R=golang-dev, bradfitz
CC=golang-dev
http://codereview.appspot.com/6553061
time: prepare for 64-bit ints

The code was trying to interpret a uint32 n as a signed quantity
and then store it in an int. For this, int(n) currently works, but when
int becomes 64 bits one must write int(int32(n)) instead, to get
the 32-bit sign extension.

Update issue 2188.

R=golang-dev, nigeltao
CC=golang-dev
http://codereview.appspot.com/6551068
text/template: allow .Field access to parenthesized expressions

Change the grammar so that field access is a proper operator.
This introduces a new node, ChainNode, into the public (but
actually internal) API of text/template/parse. For
compatibility, we only use the new node type for the specific
construct, which was not parseable before. Therefore this
should be backward-compatible.

Before, .X.Y was a token in the lexer; this CL breaks it out
into .Y applied to .X. But for compatibility we mush them
back together before delivering. One day we might remove
that hack; it's the simple TODO in parse.go/operand.

This change also provides grammatical distinction between
        f
and
        (f)
which might permit function values later, but not now.

Fixes issue 3999.

R=golang-dev, dsymonds, gri, rsc, mikesamuel
CC=golang-dev
http://codereview.appspot.com/6494119
syscall: prepare for 64-bit ints

This CL fixes code that incorrectly assumes that int is 32 bits wide.
Specifically, the socketpair system call expects a pointer to a pair
of int32s, not a pair of ints. Fix this inside the wrappers without
changing the APIs.

Update issue 2188.

R=golang-dev, r
CC=golang-dev
http://codereview.appspot.com/6552063
test: minor fixes in run and testlib

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
http://codereview.appspot.com/6547065
test: prepare for 64-bit ints

Minor tweaks to avoid assuming that int is always 32 bits.

Update issue 2188.

R=golang-dev, r
CC=golang-dev
http://codereview.appspot.com/6553062
exp/locale/collate/tools/colcmp: implementation of colcmp tool used for comparing
various implementation of collation.  The tool provides commands for soring,
regressing one implementation against another, and benchmarking.
Currently it includes collation implementations for the Go collator, ICU,
and one using Darwin's CoreFoundation framework.
To avoid building this tool in the default build, the colcmp tag has been
added to all files. This allows other tools/colcmp in this directory (e.g. it may make
sense to move maketables here) to be put in this directory as well.

R=r, rsc, mpvl
CC=golang-dev
http://codereview.appspot.com/6496118
compress/flate: move the history buffer out of the decompressor struct.

I'm not exactly sure why there's a performance gain, but it seems like
an easy win. Maybe it's a cache line thing. Maybe it's that
unsafe.Sizeof(decompressor{}) drops to below unmappedzero, so that
checkref/checkoffset don't need to insert TESTB instructions. Maybe
it's less noise for the conservative garbage collector. Maybe it's
something else.

compress/flate benchmarks:
BenchmarkDecodeDigitsSpeed1e4          378628       349906   -7.59%
BenchmarkDecodeDigitsSpeed1e5         3481976      3204898   -7.96%
BenchmarkDecodeDigitsSpeed1e6        34419500     31750660   -7.75%
BenchmarkDecodeDigitsDefault1e4        362317       335562   -7.38%
BenchmarkDecodeDigitsDefault1e5       3290032      3107624   -5.54%
BenchmarkDecodeDigitsDefault1e6      30542540     28937480   -5.26%
BenchmarkDecodeDigitsCompress1e4       362803       335158   -7.62%
BenchmarkDecodeDigitsCompress1e5      3294512      3114526   -5.46%
BenchmarkDecodeDigitsCompress1e6     30514940     28927090   -5.20%
BenchmarkDecodeTwainSpeed1e4           412818       389521   -5.64%
BenchmarkDecodeTwainSpeed1e5          3475780      3288908   -5.38%
BenchmarkDecodeTwainSpeed1e6         33629640     31931420   -5.05%
BenchmarkDecodeTwainDefault1e4         369736       348850   -5.65%
BenchmarkDecodeTwainDefault1e5        2861050      2721383   -4.88%
BenchmarkDecodeTwainDefault1e6       27120120     25862050   -4.64%
BenchmarkDecodeTwainCompress1e4        372057       350822   -5.71%
BenchmarkDecodeTwainCompress1e5       2855109      2718664   -4.78%
BenchmarkDecodeTwainCompress1e6      26987010     26336030   -2.41%

image/png benchmarks:
BenchmarkDecodeGray               1841839      1802251   -2.15%
BenchmarkDecodeNRGBAGradient      7115318      6933280   -2.56%
BenchmarkDecodeNRGBAOpaque        6135892      6013284   -2.00%
BenchmarkDecodePaletted           1153313      1114302   -3.38%
BenchmarkDecodeRGB                5619404      5511190   -1.93%

R=rsc, r
CC=golang-dev
http://codereview.appspot.com/6533048