spec and implementation disagree with respect to label declarations

R=rsc
DELTA=19  (19 added, 0 deleted, 0 changed)
OCL=26284
CL=26336

test/bugs/bug140.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() {
+	if {} else L: ;
+	if {} else L: main() ;
+}
+
+/*
+These should be legal according to the spec.
+bug140.go:6: syntax error near L
+bug140.go:7: syntax error near L
+*/

test/golden.out

@@ -136,6 +136,11 @@ bugs/bug139.go:7: fatal error: naddr: ONAME class x 5
 
 BUG should compile
 
+=========== bugs/bug140.go
+bugs/bug140.go:6: syntax error near L
+bugs/bug140.go:7: syntax error near L
+BUG should compile
+
 =========== fixedbugs/bug016.go
 fixedbugs/bug016.go:7: constant -3 overflows uint