go_spec: primality is elusive This time for sure.
go_spec: primality is elusive
This time for sure.

R=golang-dev, rsc
CC=golang-dev
http://codereview.appspot.com/5634046
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go