misc/nacl: add debugging instructions

LGTM=dave, minux
R=golang-codereviews, dave, minux
CC=golang-codereviews, rsc
https://codereview.appspot.com/122570043
cmd/gc: disallow pointer constants

Fixes issue 7760.

LGTM=iant
R=iant, remyoudompheng
CC=golang-codereviews
https://codereview.appspot.com/130720043

Committer: Ian Lance Taylor <iant@golang.org>
runtime: fix getgcmask
bv.data is an array of uint32s but the code was using
offsets computed for an array of bytes.
Add a test for stack GC info.
Fixes issue 8531.

LGTM=rsc
R=golang-codereviews
CC=golang-codereviews, khr, rsc
https://codereview.appspot.com/124450043
fmt: fix size returned on fast path of ReadRune
Fixes issue 8512.

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://codereview.appspot.com/130090043
cmd/go: fix a couple of errors found by "go vet"

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://codereview.appspot.com/127410043
A+C: Henning Schmiedehausen (individual CLA)

Generated by a+c.

R=gobot
CC=golang-codereviews
https://codereview.appspot.com/130140043
cmd/dist: goc2c ignores GOROOT_FINAL

When building golang, the environment variable GOROOT_FINAL can be set
to indicate a different installation location from the build
location. This works fine, except that the goc2c build step embeds
line numbers in the resulting c source files that refer to the build
location, no the install location.

This would not be a big deal, except that in turn the linker uses the
location of runtime/string.goc to embed the gdb script in the
resulting binary and as a net result, the debugger now complains that
the script is outside its load path (it has the install location
configured).

See https://code.google.com/p/go/issues/detail?id=8524 for the full
description.

Fixes issue 8524.

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://codereview.appspot.com/128230046

Committer: Ian Lance Taylor <iant@golang.org>
crypto/x509: SystemRootsError style tweaks, document in Verify

In retrospect this should've been a variable instead of a type,
but oh well.

LGTM=agl
R=agl
CC=golang-codereviews
https://codereview.appspot.com/129250044
cmd/ld: fix operator precedence

LGTM=rsc
R=gobot, dave
CC=golang-codereviews, iant, rsc
https://codereview.appspot.com/114420043

Committer: Dave Cheney <dave@cheney.net>
cmd/ld: fix operator precedence

Fixes issue 8480.

This CL reapplies CL 114420043. This attempt doesn't blow up when encountering hidden symbols.

LGTM=minux
R=minux
CC=golang-codereviews
https://codereview.appspot.com/128310043
runtime: mark with non-atomic operations when GOMAXPROCS=1
Perf builders show 3-5% GC pause increase with GOMAXPROCS=1 when marking with atomic ops:
http://goperfd.appspot.com/perfdetail?commit=a8a6e765d6a87f7ccb71fd85a60eb5a821151f85&commit0=3b864e02b987171e05e2e9d0840b85b5b6476386&kind=builder&builder=linux-amd64&benchmark=http

LGTM=rlh
R=golang-codereviews, rlh
CC=dave, golang-codereviews, khr, rsc
https://codereview.appspot.com/128340043
Merge branch 'master' into gitfix