Fix dart2dart and dart2js build.

lib/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');
 
 #import('../tree/tree.dart');
 #import('../scanner/scannerlib.dart');
@@ skipping 323 matching lines @@
   get cachedNode() => unsupported();
   get functionSignature() => unsupported();
   get patch() => unsupported();
   get defaultImplementation() => unsupported();
   bool get isPatched() => unsupported();
   setPatch(patch) => unsupported();
   computeSignature(compiler) => unsupported();
   requiredParameterCount(compiler) => unsupported();
   optionalParameterCount(compiler) => unsupported();
   parameterCount(copmiler) => unsupported();
+
+  getLibrary() => enclosingElement.getLibrary();
 }
 
 class ContainerElement extends Element {
   Link<Element> localMembers = const EmptyLink<Element>();
 
   ContainerElement(name, kind, enclosingElement)
     : super(name, kind, enclosingElement);
 
   void addMember(Element element, DiagnosticListener listener) {
     localMembers = localMembers.prepend(element);
@@ skipping 1203 matching lines @@
   String toString() => "${enclosingElement.toString()}.${name.slowToString()}";
 
   Token position() => cachedNode.getBeginToken();
 
   TypeVariableElement cloneTo(Element enclosing, DiagnosticListener listener) {
     TypeVariableElement result =
         new TypeVariableElement(name, enclosing, cachedNode, type, bound);
     return result;
   }
 }