Recognize gccgo error messages.
Recognize gccgo error messages.

rename1.go:10:8: error: expected type
rename1.go:11:10: error: expected function
rename1.go:13:8: error: incompatible types in binary expression

R=rsc
http://go/go-review/1015013
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go