Fix for gccgo, which uses a package prefix.

R=rsc
CC=golang-dev
https://golang.org/cl/198046

test/fixedbugs/bug248.dir/bug2.go

@@ -37,11 +37,11 @@ func main() {
 	// check that reflect paths are correct,
 	// meaning that reflect data for v0, v1 didn't get confused.
 
-	// path is full (rooted) path name.  check suffix only.
-	if s := reflect.Typeof(v0).PkgPath(); !strings.HasSuffix(s, "/bug0") {
+	// path is full (rooted) path name.  check suffix for gc, prefix for gccgo
+	if s := reflect.Typeof(v0).PkgPath(); !strings.HasSuffix(s, "/bug0") && !strings.HasPrefix(s, "bug0") {
 		panicln("bad v0 path", len(s), s)
 	}
-	if s := reflect.Typeof(v1).PkgPath(); !strings.HasSuffix(s, "/bug1") {
+	if s := reflect.Typeof(v1).PkgPath(); !strings.HasSuffix(s, "/bug1") && !strings.HasPrefix(s, "bug1") {
 		panicln("bad v1 path", s)
 	}