No longer continue assuming package main.

Fixes #4776.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/12677043

Original CL by rsc (11916045):

The motivation for disallowing them was RFC 4180 saying
"The last field in the record must not be followed by a comma."
I believe this is an admonition to CSV generators, not readers.
When reading, anything followed by a comma is not the last field.

Fixes #5892.

R=golang-dev, rsc, r
CC=golang-dev
https://golang.org/cl/12294043

Pseudo-instructions MOVBS and MOVHS are used to clarify
the semantics of short integers vs. registers:
 * 8-bit and 16-bit values in registers are assumed to always
   be zero-extended or sign-extended depending on their type.
 * MOVB is truncation or move of an already extended value
   between registers.
 * MOVBU enforces zero-extension at the destination (register).
 * MOVBS enforces sign-extension at the destination (register).
And similarly for MOVH/MOVS/MOVHU.

The linker is adapted to assemble MOVB and MOVH to an ordinary
mov. Also a peephole pass in 5g that aims at eliminating
redundant zero/sign extensions is improved.

encoding/binary:
benchmark                              old ns/op    new ns/op    delta
BenchmarkReadSlice1000Int32s              220387       217185   -1.45%
BenchmarkReadStruct                        12839        12910   +0.55%
BenchmarkReadInts                           5692         5534   -2.78%
BenchmarkWriteInts                          6137         6016   -1.97%
BenchmarkPutUvarint32                        257          241   -6.23%
BenchmarkPutUvarint64                        812          754   -7.14%
benchmark                               old MB/s     new MB/s  speedup
BenchmarkReadSlice1000Int32s               18.15        18.42    1.01x
BenchmarkReadStruct                         5.45         5.42    0.99x
BenchmarkReadInts                           5.27         5.42    1.03x
BenchmarkWriteInts                          4.89         4.99    1.02x
BenchmarkPutUvarint32                      15.56        16.57    1.06x
BenchmarkPutUvarint64                       9.85        10.60    1.08x

crypto/des:
benchmark                              old ns/op    new ns/op    delta
BenchmarkEncrypt                            7002         5169  -26.18%
BenchmarkDecrypt                            7015         5195  -25.94%
benchmark                               old MB/s     new MB/s  speedup
BenchmarkEncrypt                            1.14         1.55    1.36x
BenchmarkDecrypt                            1.14         1.54    1.35x

strconv:
benchmark                              old ns/op    new ns/op    delta
BenchmarkAtof64Decimal                       457          385  -15.75%
BenchmarkAtof64Float                         574          479  -16.55%
BenchmarkAtof64FloatExp                     1035          906  -12.46%
BenchmarkAtof64Big                          1793         1457  -18.74%
BenchmarkAtof64RandomBits                   2267         2066   -8.87%
BenchmarkAtof64RandomFloats                 1416         1194  -15.68%
BenchmarkAtof32Decimal                       451          379  -15.96%
BenchmarkAtof32Float                         547          435  -20.48%
BenchmarkAtof32FloatExp                     1095          986   -9.95%
BenchmarkAtof32Random                       1154         1006  -12.82%
BenchmarkAtoi                               1415         1380   -2.47%
BenchmarkAtoiNeg                            1414         1401   -0.92%
BenchmarkAtoi64                             1744         1671   -4.19%
BenchmarkAtoi64Neg                          1737         1662   -4.32%

Fixes #1837.

R=rsc, dave, bradfitz
CC=golang-dev
https://golang.org/cl/12424043

Fixes #6043.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/12693043

Fixes #6034.

R=golang-dev, bradfitz, alex.brainman, dan.kortschak
CC=golang-dev
https://golang.org/cl/12311044

By separating finding the end of the comment from the end of the action,
we can diagnose malformed comments better.
Also tweak the documentation to make the comment syntax clearer.

Fixes #6022.

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/12570044

g% 6c ~/x.c
/Users/rsc/x.c:1 duplicate types given: STRUCT s and VOID
/Users/rsc/x.c:1 no return at end of function: f
g%

Fixes #6083.

R=ken2
CC=golang-dev
https://golang.org/cl/12691043

See issue 4949 for a full explanation.

Allocs go from 1 to zero in the non-addressable case.
Fixes #4949.

BenchmarkInterfaceBig             90           14  -84.01%
BenchmarkInterfaceSmall           14           14   +0.00%

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12646043

R=golang-dev, bradfitz
CC=golang-dev, ryanslade
https://golang.org/cl/12588044

Unlike the existing net package own pollster, runtime-integrated
network pollster on BSD variants, actually kqueue, requires a socket
that has beed passed to syscall.Listen previously for a stream
listener.

This CL separates pollDesc.Init of Unix network pollster from newFD
to avoid any breakages in the transition from Unix network pollster
to runtime-integrated pollster. Upcoming CLs will rearrange the call
order of pollster and syscall functions like the following;

- For dialers that open active connections, pollDesc.Init will be
  called in between syscall.Bind and syscall.Connect.

- For stream listeners that open passive stream connections,
  pollDesc.Init will be called just after syscall.Listen.

- For datagram listeners that open datagram connections,
  pollDesc.Init will be called just after syscall.Bind.

This is in preparation for runtime-integrated network pollster for BSD
variants.

Update #5199

R=dvyukov, bradfitz
CC=golang-dev
https://golang.org/cl/12663043

Having a trailing dot in the string doesn't really simplify
the checking loop in isDomainName. Avoid this unnecessary allocation.
Also make the valid domain names more explicit by adding some more
test cases.

benchmark            old ns/op    new ns/op    delta
BenchmarkDNSNames       2420.0        983.0  -59.38%

benchmark           old allocs   new allocs    delta
BenchmarkDNSNames           12            0  -100.00%

benchmark            old bytes    new bytes    delta
BenchmarkDNSNames          336            0  -100.00%

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12662043

Renders code coverage as an overlay, replicating the look of the
HTML that go tool cover produces.

Also some cleanups.

R=adonovan, bradfitz
CC=golang-dev
https://golang.org/cl/12684043

R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/12603045

MOVBS and MOVHS are defined as duplicates of MOVB and MOVH,
and perform sign-extension moving.
No change is made to code generation.

Update #1837

R=rsc, bradfitz
CC=golang-dev
https://golang.org/cl/12682043

- adjusted test files so that they actually type-check
- adjusted go1.txt, go1.1.txt, next.txt
- to run, provide build tag: api_tool

Fixes #4538.

R=bradfitz
CC=golang-dev
https://golang.org/cl/12300043

The ResponseWriter's ReadFrom method was causing side effects on
the output before any data was read.

Now, bail out early and do a normal copy (which does a read
before writing) when our input and output are known to not to
be the pair of types we need for sendfile.

Fixes #5660

R=golang-dev, rsc, nightlyone
CC=golang-dev
https://golang.org/cl/12632043

I moved the pointer block from one end of the frame
to the other toward the end of working on the last CL,
and of course that made the optimization no longer work.

Now it works again:

0030 (bug361.go:12) DATA    gclocals·0+0(SB)/4,$4
0030 (bug361.go:12) DATA    gclocals·0+4(SB)/4,$3
0030 (bug361.go:12) GLOBL   gclocals·0+0(SB),8,$8

Fixes arm build (this time for sure!).

TBR=golang-dev
CC=cshapiro, golang-dev, iant
https://golang.org/cl/12627044

Sort non-pointer-containing data to the low end of the
stack frame, and make the bitmaps only cover the
pointer-containing top end.

Generates significantly less garbage collection bitmap
for programs with large byte buffers on the stack.

Only 2% shorter for godoc, but 99.99998% shorter
in some test cases.

Fixes arm build.

TBR=golang-dev
CC=cshapiro, golang-dev, iant
https://golang.org/cl/12541047

We weren't seeing additions. (stuff to put in next.txt)

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/12678043

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/12519046

R=gri
CC=golang-dev
https://golang.org/cl/12639043

The receiver name is optional. when Method's receiver name messing,
the functionList regex can't match the Method,
e.g. `func (*T) ProtoMessage() {}`.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12530044

Fixes #5900.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12669043

Individual variables bigger than 10 MB are now
moved to the heap, as if they had escaped on
their own.

This avoids ridiculous stacks for programs that
do things like
        x := [1<<30]byte{}
        ... use x ...

If 10 MB is too small, we can raise the limit.

Fixes #6077.

R=ken2
CC=golang-dev
https://golang.org/cl/12650045

Readdir's result should never contain a nil.

Fixes #5960.

R=golang-dev, rsc, bradfitz
CC=golang-dev
https://golang.org/cl/12261043

Fixes #5334.

R=golang-dev, dave, rsc
CC=golang-dev
https://golang.org/cl/8653047

R=golang-dev
CC=golang-dev
https://golang.org/cl/12634044

Generated by addca.

R=gobot
CC=golang-dev
https://golang.org/cl/12671043

Fixes #4938.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12657044

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12585044

GetQueuedCompletionStatusEx allows to dequeue a batch of completion
notifications, which is more efficient than dequeueing one by one.

benchmark                           old ns/op    new ns/op    delta
BenchmarkClientServerParallel4         100605        90945   -9.60%
BenchmarkClientServerParallel4-2        90225        74504  -17.42%

R=golang-dev, alex.brainman
CC=golang-dev
https://golang.org/cl/12436044

This allows to skip GetQueuedCompletionStatus if an IO operation completes synchronously.
benchmark                    old ns/op    new ns/op    delta
BenchmarkTCP4Persistent          27669        25863   -6.53%
BenchmarkTCP4Persistent-2        18173        15908  -12.46%
BenchmarkTCP4Persistent-4        10390         9766   -6.01%

R=golang-dev, mikioh.mikioh, alex.brainman
CC=golang-dev
https://golang.org/cl/12409044

Fixes #5896.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12645043

Fixes #6058.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12643043

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/12642043

s/commandLine/CommandLine/g

Fixes #4209.

R=golang-dev, dsymonds, bradfitz
CC=golang-dev
https://golang.org/cl/12587043

Fixes bug 6055.

R=golang-dev, bradfitz, dvyukov, khr
CC=golang-dev
https://golang.org/cl/12536045

In prep for Robert's forthcoming cmd/api rewrite which
depends on the go.tools subrepo, we'll need to be more
careful about how and when we run cmd/api.

Rather than implement this policy in both run.bash and
run.bat, this change moves the policy and mechanism into
cmd/api/run.go, which will then evolve.

The plan is in a TODO in run.go.

R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/12482044

Fixes #6061.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12609043

The test takes up to 64 seconds on windows builders.
I've tried to reduce number of iterations in the test,
but it does not affect run time.
Fixes #6054.

R=golang-dev, alex.brainman
CC=golang-dev
https://golang.org/cl/12531043