label declarations not handled properly

R=rsc
DELTA=27  (27 added, 0 deleted, 0 changed)
OCL=25015
CL=25015

test/bugs/bug137.go

+// $G $D/$F.go || echo BUG should compile
+
+// 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
+
+func main() {
+L1:
+L2:	for i := 0; i < 10; i++ {
+		print(i);
+		break L2;
+	}
+
+L3: ;
+L4:	for i := 0; i < 10; i++ {
+		print(i);
+		break L4;
+	}
+}
+
+/*
+bug137.go:9: break label is not defined: L2
+bug137.go:15: break label is not defined: L4
+*/

test/golden.out

@@ -166,6 +166,11 @@ BUG: compilation succeeds incorrectly
 =========== bugs/bug136.go
 BUG: should not compile
 
+=========== bugs/bug137.go
+bugs/bug137.go:9: break label is not defined: L2
+bugs/bug137.go:15: break label is not defined: L4
+BUG should compile
+
 =========== fixedbugs/bug016.go
 fixedbugs/bug016.go:7: overflow converting constant to uint