regexp: exclude exhaustive RE2 test from running under race detector.

It is an expensive test to run, and even more so with -race,
and causes timeouts on builders. It is doubtful that it would
find a race that other tests in this package wouldn't, so there
is little loss in excluding it.

Update issue 5837.

R=golang-dev, dave
CC=golang-dev
https://codereview.appspot.com/11568043
runtime: prevent sysmon from polling network excessivly
If the network is not polled for 10ms, sysmon starts polling network
on every iteration (every 20us) until another thread blocks in netpoll.
Fixes issue 5922.

R=golang-dev, iant
CC=golang-dev
https://codereview.appspot.com/11569043
runtime: hide mheap from GC
It contains pointers to first blocks of lots of spans.

R=golang-dev, iant
CC=golang-dev
https://codereview.appspot.com/11416046
test: fix error output in the test

R=golang-dev, iant
CC=golang-dev
https://codereview.appspot.com/11432046
runtime: prevent GC from seeing the contents of a frame in runfinq
This holds the last finalized object and arguments to its finalizer.
Fixes issue 5348.

R=golang-dev, iant
CC=golang-dev
https://codereview.appspot.com/11454044
runtime: cleanup: use ArgsSizeUnknown to mark all functions
whose argument size is unknown (C vararg functions, and
assembly code without an explicit specification).

We used to use 0 to mean "unknown" and 1 to mean "zero".
Now we use ArgsSizeUnknown (0x80000000) to mean "unknown".

R=golang-dev, rsc
CC=golang-dev
https://codereview.appspot.com/11590043
debug/gosym: put pclinetest file in temporary directory
where it belongs.

R=rsc
CC=golang-dev
https://codereview.appspot.com/11596043
cmd/dist: generate offsets for P structure

So far no checked-in assembly needs these,
but it matches having them for M and G.
I needed these for some manual testing.

R=golang-dev, dvyukov
CC=golang-dev
https://codereview.appspot.com/11595043
runtime: use funcdata to supply garbage collection information

This CL introduces a FUNCDATA number for runtime-specific
garbage collection metadata, changes the C and Go compilers
to emit that metadata, and changes the runtime to expect it.

The old pseudo-instructions that carried this information
are gone, as is the linker code to process them.

R=golang-dev, dvyukov, cshapiro
CC=golang-dev
https://codereview.appspot.com/11406044
cmd/gc, cmd/ld: fix build: remove unused var, use correct var in printf

Fixes issue 5924.

R=golang-dev, khr, rsc
CC=golang-dev
https://codereview.appspot.com/11606043
cmd/ld, runtime: remove unused fields from Func

R=golang-dev, r
CC=golang-dev
https://codereview.appspot.com/11604043
cmd/dist, cmd/go: enable more warnings, make clang errors legible

This does not change the default compiler on OS X to clang.
It appears that for now we can keep using gcc as long as we
enable a few more warning settings that are on-by-default
elsewhere.

R=golang-dev, bradfitz, dave
CC=golang-dev
https://codereview.appspot.com/11610044
libmach,lib9: override unused parameter warnings (fixes windows build)

R=golang-dev, dave
CC=golang-dev
https://codereview.appspot.com/11620044
libmach,lib9: override unused parameter warnings (fixes netbsd and openbsd builds)

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/11623043
libmach: support more 386/amd64 instructions

R=golang-dev, dave, bradfitz, rsc
CC=golang-dev
https://codereview.appspot.com/10030043
Merge branch 'master' into gitfix