cmd/gc: racewalk: collect stack traces in sync and sync/atomic W/o this change stack traces do not show from where sync.Once() or atomic.XXX was called. This change add funcenter/exit instrumentation to sync/sync.atomic packages.
cmd/gc: racewalk: collect stack traces in sync and sync/atomic
W/o this change stack traces do not show from where sync.Once()
or atomic.XXX was called.
This change add funcenter/exit instrumentation to sync/sync.atomic
packages.

R=golang-dev
CC=golang-dev
https://codereview.appspot.com/6854112

h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang