Fix an issue resolving paths when remote debugging.

editor/tools/plugins/com.google.dart.tools.debug.core/src/com/google/dart/tools/debug/core/server/VmLibraryRef.java

 /*
  * Copyright 2012 Dart project authors.
  * 
  * Licensed under the Eclipse Public License v1.0 (the "License"); you may not use this file except
  * in compliance with the License. You may obtain a copy of the License at
  * 
  * http://www.eclipse.org/legal/epl-v10.html
  * 
  * Unless required by applicable law or agreed to in writing, software distributed under the License
  * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
@@ skipping 63 matching lines @@
    * Returns whether this library ref is for the 'dart:async' library.
    */
   public boolean isAsync() {
     return "dart:async".equals(url);
   }
 
   /**
    * Returns whether this library ref is for an internal Dart library.
    */
   public boolean isInternal() {
-    return "dart:_internal".equals(url) || "dart:builtin".equals(url)
-        || "dart:nativewrappers".equals(url);
+    return url.startsWith("dart:_") || "dart:nativewrappers".equals(url);
   }
 
   @Override
   public String toString() {
     return "[" + id + "," + url + "]";
   }
 }