Re-apply "Clean up the patch file for the isolate library by introducing a new buitlin library: iso…

sdk/lib/_internal/compiler/implementation/elements/elements.dart

 // Copyright (c) 2012, 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.
 
 library elements;
 
 import 'dart:uri';
 
 // TODO(ahe): Rename prefix to 'api' when VM bug is fixed.
 import '../../compiler.dart' as api_e;
@@ skipping 1752 matching lines @@
    */
   bool isSubclassOf(ClassElement cls) {
     for (ClassElement s = this; s != null; s = s.superclass) {
       if (identical(s, cls)) return true;
     }
     return false;
   }
 
   bool isInterface() => false;
   bool isNative() => nativeTagInfo != null;
+  void setNative(String name) {
+    nativeTagInfo = new SourceString(name);
+  }
   int get hashCode => id;
 
   Scope buildScope() => new ClassScope(enclosingElement.buildScope(), this);
 
   String toString() {
     if (origin != null) {
       return 'patch ${super.toString()}';
     } else if (patch != null) {
       return 'origin ${super.toString()}';
     } else {
@@ skipping 375 matching lines @@
 
   MetadataAnnotation ensureResolved(Compiler compiler) {
     if (resolutionState == STATE_NOT_STARTED) {
       compiler.resolver.resolveMetadataAnnotation(this);
     }
     return this;
   }
 
   String toString() => 'MetadataAnnotation($value, $resolutionState)';
 }