Make [EnumClassElement.enumValues] a [List].

pkg/compiler/lib/src/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 '../constants/expressions.dart';
 import '../tree/tree.dart';
 import '../util/util.dart';
@@ skipping 1412 matching lines @@
 abstract class MixinApplicationElement extends ClassElement {
   ClassElement get mixin;
   InterfaceType get mixinType;
   void set mixinType(InterfaceType value);
   void addConstructor(FunctionElement constructor);
 }
 
 /// Enum declaration.
 abstract class EnumClassElement extends ClassElement {
   /// The static fields implied by the enum values.
-  Iterable<FieldElement> get enumValues;
+  List<FieldElement> get enumValues;
 }
 
 /// The label entity defined by a labeled statement.
 abstract class LabelDefinition extends Entity {
   Label get label;
   String get labelName;
   JumpTarget get target;
 
   bool get isTarget;
   bool get isBreakTarget;
@@ skipping 177 matching lines @@
   bool get isDeclaredByField;
 
   /// Returns `true` if this member is abstract.
   bool get isAbstract;
 
   /// If abstract, [implementation] points to the overridden concrete member,
   /// if any. Otherwise [implementation] points to the member itself.
   Member get implementation;
 }