cmd/go: kill test.out after 1 minute
cmd/go: kill test.out after 1 minute

Will have to do better but this is enough to
stop the builders from hanging, I hope.

R=golang-dev, dsymonds, adg
CC=golang-dev
http://codereview.appspot.com/5533066
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go