cmd/cc: emit size of locals.  Will be used for stack copying.

R=cshapiro, dvyukov, khr, rsc
CC=golang-dev
https://codereview.appspot.com/10005044
cmd/go: add coverage analysis
This feature is not yet ready for real use. The CL marks a bite-sized
piece that is ready for review. TODOs that remain:
        provide control over output
        produce output without setting -v
        make work on reflect, sync and time packages
                (fail now due to link errors caused by inlining)
        better documentation
Almost all packages work now, though, if clumsily; try:
        go test -v -cover=count encoding/binary

R=rsc
CC=gobot, golang-dev, remyoudompheng
https://codereview.appspot.com/10050045
cmd/gc: avoid creating circular lists when compiling with race detector.

Fixes issue 5431.

R=dvyukov, remyoudompheng, rsc
CC=gobot, golang-dev
https://codereview.appspot.com/9910043
cmd/gc: compute initialization order for top-level blank vars too.

Fixes issue 5244.

R=golang-dev, rsc, iant, r, daniel.morsing
CC=golang-dev
https://codereview.appspot.com/8601044
runtime: rename _rt0_$GOARCH to _rt0_go

There's no reason to use a different name on each architecture,
and doing so makes it impossible for portable code to refer to
the original Go runtime entry point. Rename it _rt0_go everywhere.

This is a global search and replace only.

R=golang-dev, bradfitz, minux.ma
CC=golang-dev
https://codereview.appspot.com/10196043
runtime: round spans_size up to page boundary
in case we have weird (not page aligned) memory limit.

R=golang-dev, rsc
CC=golang-dev
https://codereview.appspot.com/10199043
cmd/ld: supply -s to gcc if -s is passed.
Fixes issue 5463.

R=golang-dev, iant
CC=golang-dev
https://codereview.appspot.com/9239045
cmd/gc: turn race detector off for tail-call method wrapper functions

It was off in the old implementation (because there was no high-level
description of the function at all). Maybe some day the race detector
should be fixed to handle the wrapper and then enabled for it, but there's
no reason that has to be today.

R=golang-dev
TBR=dvyukov
CC=golang-dev
https://codereview.appspot.com/10037045
cmd/gc: save local var list before inlining

This avoids problems with inlining in genwrappers, which
occurs after functions have been compiled.  Compiling a
function may cause some unused local vars to be removed from
the list.  Since a local var may be unused due to
optimization, it is possible that a removed local var winds up
beingused in the inlined version, in which case hilarity
ensues.

Fixes issue 5515.

R=golang-dev, khr, dave
CC=golang-dev
https://codereview.appspot.com/10210043
cmd/go: use -o option of cover tool
Separates correct from erroneous output so errors running the tool will appear
in the log.

R=rsc
CC=golang-dev
https://codereview.appspot.com/10191043
C: add Josh Hoak (Google CLA).

R=golang-dev, rsc
CC=golang-dev, jhoak
https://codereview.appspot.com/10217043