Validate the target of break and continue statments from within a switch

compiler/java/com/google/dart/compiler/resolver/LabelElement.java

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 package com.google.dart.compiler.resolver;
 
 public interface LabelElement extends Element {
+  
+  public enum LabeledStatementType {
+    STATEMENT,
+    SWITCH_MEMBER_STATEMENT,
+    SWITCH_STATEMENT,
+  }
+  
   /**
    * Returns the innermost function where this label is defined.
    */
   public MethodElement getEnclosingFunction();
+  
+  public LabeledStatementType getStatementType();
 }