bug: cannot take len() of a constant string

R=r
OCL=13989
CL=13989

test/bugs/bug087.go

+// $G $D/$F.go || echo BUG: fails incorrectly
+
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+const s string = "foo";
+
+func main() {
+	i := len(s);  // should be legal to take len() of a constant
+}
+
+/*
+uetli:~/Source/go1/test/bugs gri$ 6g bug087.go
+bug087.go:6: illegal combination of literals LEN 9
+bug087.go:6: illegal combination of literals LEN 9
+*/

test/golden.out

@@ -264,6 +264,11 @@ BUG: fails incorrectly
 4882
 BUG: succeeds incorrectly
 
+=========== bugs/bug087.go
+bugs/bug087.go:8: illegal combination of literals LEN 9
+bugs/bug087.go:8: illegal combination of literals LEN 9
+BUG: fails incorrectly
+
 =========== fixedbugs/bug000.go
 
 =========== fixedbugs/bug001.go