Match gccgo error messages.

bug165.go:13:6: error: invalid recursive type 'S'

This is a different line from the 6g error message, which is
"invalid map key type".  I accomodated both compilers by
merging the line.

bug188.go:13:2: error: unexpected reference to package

I made the error message less specific, which I think is fine
here.

R=rsc
DELTA=2  (0 added, 0 deleted, 2 changed)
OCL=33398
CL=33426

test/fixedbugs/bug165.go

@@ -11,5 +11,5 @@ type I interface {
 }
 
 type S struct {
-	m map[S] bool;	// ERROR "map key type|complete"
+	m map[S] bool;	// ERROR "map key type"
 }

test/fixedbugs/bug188.go

@@ -10,5 +10,5 @@ import "sort"
 
 func main() {
 	var x int;
-	sort(x);	// ERROR "package.*selector"
+	sort(x);	// ERROR "package"
 }