reflect: test that PtrTo returns types that match program types
reflect: test that PtrTo returns types that match program types

The gccgo compiler was failing this test.

R=golang-dev, gri
CC=golang-dev
http://codereview.appspot.com/5631046
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go