test: don't rely on order of unrelated imports in bug191

There is no necessary relationship between the imports of the
packages a and b, and gccgo happens to import them in a
different order, leading to different output.  This ordering
is not the purpose of the test in any case.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/40400043

test/fixedbugs/bug191.dir/main.go

@@ -11,4 +11,7 @@ var _ T
 var _ V
 
 func main() {
+	if A != 1 || B != 2 {
+		panic("wrong vars")
+	}
 }