Implement what Chrome calls socket "late binding". See:
https://insouciant.org/tech/connection-management-in-chromium/

In a nutshell, if our HTTP client needs a TCP connection to a
remote host and there's not an idle one available, rather than
kick off a dial and wait for that specific dial, we instead
kick off a dial and wait for either our own dial to finish, or
any other TCP connection to that same host to become
available.

The implementation looks like a classic "Learning Go
Concurrency" slide.

Chrome's commit and numbers:
http://src.chromium.org/viewvc/chrome?view=rev&revision=36230

R=golang-dev, daniel.morsing, adg
CC=golang-dev
https://golang.org/cl/7587043

Change 231af8ac63aa (CL 7314062) made runtime.enteryscall()
set m->mcache = nil, which means that we can no longer use
syscall.errstr in syscall.Syscall and syscall.Syscall6, since it
requires a new buffer to be allocated for holding the error string.
Instead, we use pre-allocated per-M storage to hold error strings
from syscalls made while in entersyscall mode, and call
runtime.findnull to calculate the lengths.

Fixes #4994.

R=rsc, rminnich, ality, dvyukov, rminnich, r
CC=golang-dev
https://golang.org/cl/7567043

This CL splits multicast listener tests into two; for IPv4 and
for IPv6. It also removes redundant test inputs and makes sure
that assignment of multicast interface to stablize the tests.

Fixes #4059.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/7565043

Instructions for use in AES hashing.  See CL#7543043

R=rsc
CC=golang-dev
https://golang.org/cl/7548043

The code would violate the contract of cmp64.

Fixes #5002.

R=rsc, golang-dev
CC=golang-dev
https://golang.org/cl/7593043

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/7595043

TBR=golang-dev
CC=golang-dev
https://golang.org/cl/7575046

R=adonovan, bradfitz
CC=golang-dev
https://golang.org/cl/7492045

    Instead of relying on gofmt's diff output (which is a unified
    diff), we manually invoke diff -n and produce an RCS format diff,
    which can easily be parsed in Emacs, with the go--apply-rcs-patch
    function.

    This fixes undocumented issues with the old implementation such as
    skipping over hunks of changes, and it fixes the documented issue
    of not being able to handle file names that include whitespace.

    It can also apply the patch on a buffer that has no file name
    attached at all.

    Last but not least, it greatly simplifies the gofmt function
    itself.

Fixes #4766.
Fixes #4475.

R=adonovan, cw, patrick.allen.higgins, sameer
CC=golang-dev
https://golang.org/cl/7516046

Move pollServer from fd_unix.go to fd_poll_unix.go.
Add pollServerInit(*NetFD) to allow custom initialization.
Add pollServer.Close(*NetFD) to allow custom finalization.
Move setDeadline() to fd_poll_unix.go to allow custom handling of deadlines.
Move newPollServer() to fd_poll_unix.go to allow custom initialization.
No logical code changes.
The next step will be to turn off fd_poll_unix.go for some platform
(I have changes for darwin/linux) and redirect it into runtime. See:
https://golang.org/cl/7569043/diff/2001/src/pkg/net/fd_poll_runtime.go

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/7513045

The deadlock episodically occurs on misc/cgo/test/TestCthread.
The problem is that starttheworld() leaves some P's with local work
without M's. Then all active M's enter into syscalls, but reject to
wake another M's due to the following check (both in entersyscallblock() and in retake()):
if(p->runqhead == p->runqtail &&
        runtime·atomicload(&runtime·sched.nmspinning) +
        runtime·atomicload(&runtime·sched.npidle) > 0)
        continue;

R=rsc
CC=golang-dev
https://golang.org/cl/7424054

Still to do: non-linux and non-amd64.
It may work on other ELF-based amd64 systems too, but untested.

"go test -ldflags -hostobj $GOROOT/misc/cgo/test" passes.

Much may yet change, but this seems a reasonable checkpoint.

R=iant
CC=golang-dev
https://golang.org/cl/7369057

Fixes #4955.

R=golang-dev, alex.brainman
CC=golang-dev
https://golang.org/cl/7563043

Ensure that accept/connect respect deadline,
even if the operation can be executed w/o blocking.
Note this changes external behavior, but it makes
it consistent with read/write.
Factor out deadline check into pollServer.PrepareRead/Write,
in preparation for edge triggered pollServer.
Ensure that pollServer.WaitRead/Write are not called concurrently
by adding rio/wio locks around connect/accept.

R=golang-dev, mikioh.mikioh, bradfitz, iant
CC=golang-dev
https://golang.org/cl/7436048

R=golang-dev, akumar
CC=golang-dev
https://golang.org/cl/7523044

R=golang-dev, akumar
CC=golang-dev
https://golang.org/cl/7564043

Fixes #4505.

R=golang-dev, mikioh.mikioh
CC=golang-dev
https://golang.org/cl/7468043

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/7551043

Fixes #4982.

R=adonovan, r
CC=golang-dev
https://golang.org/cl/7537043

Also:
- cleaner handling of constants w/ unknown value
- removed several TODOs

R=adonovan
CC=golang-dev
https://golang.org/cl/7473043

Fixes #4974.

R=rsc, bradfitz, r
CC=golang-dev
https://golang.org/cl/7545043

It's a common mistake to build a recursive String method; explain it well and
show how to avoid it.

R=golang-dev, bradfitz, adg
CC=golang-dev
https://golang.org/cl/7486049

See also https://golang.org/cl/7520044

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7533044

Before:
BenchmarkHeaderWriteSubset  500000  2354 ns/op  197 B/op  2 allocs/op
After:
BenchmarkHeaderWriteSubset 1000000  2085 ns/op    0 B/op  0 allocs/op

Fixes #3761

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7508043

Also emit cgo_ldflag pragmas.

R=golang-dev, remyoudompheng, iant
CC=golang-dev
https://golang.org/cl/7530043

TBR=bradfitz
CC=golang-dev
https://golang.org/cl/7540043

TBR=golang-dev
CC=golang-dev
https://golang.org/cl/7539043

Some IDS somewhere thinks "Go http package" is a virus.
Make it something else for Go 1.1. Dumb but easy.

R=golang-dev, bradfitz, minux.ma
CC=golang-dev
https://golang.org/cl/7532043

This installs type checking into go vet.
(To be removed before releasing Go 1.1)

R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/7528044

We can enable/disable type checking with a build tag.
Should simplify cutting the go1.1 distribution free of go/types.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7482045

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/7523043

Fixes #4522.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7502044

BenchmarkSplit1     77984460     24131380  -69.06%

R=golang-dev, rsc, minux.ma, dave, extemporalgenome
CC=golang-dev
https://golang.org/cl/7458043

Generated by addca.

R=gobot
CC=golang-dev
https://golang.org/cl/7473047

R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/7486048

Fixes #4841.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7475046

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/7529043

Now the default startup is that the program begins at _rt0_amd64_$GOOS,
which sets DI = argc, SI = argv and jumps to _rt0_amd64.

This makes the _rt0_amd64 entry match the expected semantics for
the standard C "main" function, which we can now provide for use when
linking against a standard C library.

R=golang-dev, devon.odell, minux.ma
CC=golang-dev
https://golang.org/cl/7525043

This CL adds compatibility for GNU Emacs 23 (fixing fontification
issues) and XEmacs >=21.5.32 (fixing a lot of issues). Earlier
versions of XEmacs will not be supported because they do not
support POSIX character classes. Because of that, we also make use
of a lot of functions that were added in 21.5.32.

A known and currently unfixable issue with XEmacs is that go-mode
will not always fontify identifiers that use unicode correctly.

All changes for XEmacs are annotated in the diff.

Note: go--position-bytes is not currently used anywhere, but will
be in a future CL.

Fixes #4927.

R=golang-dev, adonovan, cw, patrick.allen.higgins, sameer
CC=golang-dev
https://golang.org/cl/7456051

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/7518044