Add a couple of workarounds for issues caused by current dart2js patch

lib/compiler/implementation/resolver.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.
 
 interface TreeElements {
   Element operator[](Node node);
   Selector getSelector(Send send);
   Type getType(TypeAnnotation annotation);
 }
 
@@ skipping 142 matching lines @@
     }
     ClassElement defaultClass = defaultType.element;
     defaultClass.ensureResolved(compiler);
     assert(defaultClass.resolutionState == ClassElement.STATE_DONE);
     assert(defaultClass.supertypeLoadState == ClassElement.STATE_DONE);
     if (defaultClass.isInterface()) {
       error(node, MessageKind.CANNOT_INSTANTIATE_INTERFACE,
             [defaultClass.name]);
     }
     // We have now established the following:
-    // [intrface] is an interface, let's say "MyInterface".
+    // [interface] is an interface, let's say "MyInterface".

[Johnni Winther, 2012/08/17 10:39:45]

[intrface] refers to the local variable so we should probably use the name in
the comment.

[Mads Ager (google), 2012/08/17 10:44:38]

Reverted this change. What a horrible variable name. ;-)

     // [defaultClass] is a class, let's say "MyClass".
 
     // If the default class implements the interface then we must use the
     // default class' name. Otherwise we look for a factory with the name
     // of the interface.
     SourceString name;
     if (defaultClass.implementsInterface(intrface)) {
       // TODO(ahe): Don't use string replacement here.
       name = new SourceString(constructor.name.slowToString().replaceFirst(
                  intrface.name.slowToString(),
@@ skipping 2257 matching lines @@
   TopScope(LibraryElement library) : super(null, library);
   Element lookup(SourceString name) {
     return library.find(name);
   }
 
   Element add(Element newElement) {
     throw "Cannot add an element in the top scope";
   }
   String toString() => '$element';
 }