Hello rsc (cc: golang-dev@googlegroups.com), I'd like you to review this change.
LGTM put "gc: " at the beginning of the description
*** Submitted as http://code.google.com/p/go/source/detail?r=939d2f28eb7e *** add missing argument to usage message. Fixes issue 912. R=rsc CC=golang-dev http://codereview.appspot.com/1819041