cmd/go: for -msan build runtime/cgo with -fsanitize=memory
The go tool used to avoid passing -fsanitize=memory when building
runtime/cgo. That was originally to avoid an msan error, but that error
was fixed anyhow for issue #13815. And building runtime/cgo with
-fsanitize=memory corrects the handling of the context traceback
function when the traceback function itself is built with
-fsanitize=memory.
Change-Id: I4bf5c3d21de6b2eb540600435ae47f5820d17464
Reviewed-on: https://go-review.googlesource.com/24855
Run-TryBot: Ian Lance Taylor <iant@golang.org> Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>