Big merge from experimental to bleeding edge.

sdk/lib/_internal/compiler/implementation/resolution/scope.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.
 
 part of resolution;
 
 abstract class Scope {
   /**
    * Adds [element] to this scope. This operation is only allowed on mutable
    * scopes such as [MethodScope] and [BlockScope].
@@ skipping 86 matching lines @@
 
   Element localLookup(SourceString name) => elements[name];
 }
 
 class MethodScope extends MutableScope {
   final Element element;
 
   MethodScope(Scope parent, this.element)
       : super(parent);
 
-  String toString() => 'MethodScope($element${elements.keys})';
+  String toString() => 'MethodScope($element${elements.keys.toList()})';
 }
 
 class BlockScope extends MutableScope {
   BlockScope(Scope parent) : super(parent);
 
-  String toString() => 'BlockScope(${elements.keys})';
+  String toString() => 'BlockScope(${elements.keys.toList()})';
 }
 
 /**
  * [ClassScope] defines the inner scope of a class/interface declaration in
  * which declared members, declared type variables, entities in the enclosing
  * scope and inherited members are available, in the given order.
  */
 class ClassScope extends TypeDeclarationScope {
   ClassElement get element => super.element;
 
@@ skipping 30 matching lines @@
 
   Element localLookup(SourceString name) => library.find(name);
   Element lookup(SourceString name) => localLookup(name);
 
   Element add(Element newElement) {
     throw "Cannot add an element to a library scope";
   }
 
   String toString() => 'LibraryScope($library)';
 }