bug117 is fixed in 6g; now an errchk

R=r
DELTA=42  (20 added, 22 deleted, 0 changed)
OCL=28295
CL=28295

test/fixedbugs/bug117.go

@@ -10,8 +10,12 @@ type PS *S
 func (p *S) get() int {
   return p.a
 }
+
 func fn(p PS) int {
-  return p.get()
+  // p has type PS, and PS has no methods.
+  // (a compiler might see that p is a pointer
+  // and go looking in S without noticing PS.)
+  return p.get()	// ERROR "undefined DOT"
 }
 func main() {
   s := S{1};

test/golden.out

@@ -85,12 +85,6 @@ abcxyz-abcxyz-abcxyz-abcxyz-abcxyz-abcxyz-abcxyz
 =========== chan/nonblock.go
 PASS
 
-=========== bugs/bug117.go
-bugs/bug117.go:9: undefined DOT get on PS
-bugs/bug117.go:9: illegal types for operand: RETURN
-	int
-BUG: should compile
-
 =========== bugs/bug132.go
 BUG: compilation succeeds incorrectly