Match gccgo error messages.
Match gccgo error messages.

bug238.go:11:7: error: invalid constant type
bug238.go:12:7: error: invalid constant type
bug238.go:13:7: error: invalid constant type
bug238.go:14:7: error: invalid constant type
bug238.go:15:7: error: invalid constant type
bug238.go:16:7: error: invalid constant type
bug238.go:17:7: error: invalid constant type

R=rsc
CC=golang-dev
http://codereview.appspot.com/194159
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go