break and continue fixes

labeled break/continue was using
first loop with any label,
not first loop with the right label.

R=ken
OCL=32453
CL=32458

test/fixedbugs/bug179.go

@@ -0,0 +1,24 @@
+// errchk $G -e $D/$F.go
+
+// 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() {
+L:
+	for {
+		for {
+			break L2;	// ERROR "L2"
+			continue L2;	// ERROR "L2"
+		}
+	}
+
+L1:
+	x := 1;
+	for {
+		break L1;	// ERROR "L1"
+		continue L1;	// ERROR "L1"
+	}
+}