Do not hide membership of implementation classes in dart:core.

tests/lib/mirrors/hierarchy_invariants_test.dart

 // Copyright (c) 2013, 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 test.hierarchy_invariants_test;
 
 import 'dart:mirrors';
 
 import 'package:expect/expect.dart';
 
+isAnonymousMixinApplication(classMirror) {

[ahe, 2013/10/15 07:14:02]

Should we have an accessor for this in the API?

+  return MirrorSystem.getName(classMirror.simpleName).contains(' with ');
+}
+
 check(classMirror) {
   if (classMirror is TypedefMirror) return;
 
   Expect.isTrue(classMirror.simpleName is Symbol);
   Expect.notEquals(null, classMirror.owner);
   Expect.isTrue(classMirror.owner is LibraryMirror);
+  if (!isAnonymousMixinApplication(classMirror)) {
+    Expect.equals(classMirror.originalDeclaration,
+                  classMirror.owner.classes[classMirror.simpleName]);
+  } else {
+    Expect.isNull(classMirror.owner.classes[classMirror.simpleName]);
+  }
   Expect.isTrue(classMirror.superinterfaces is List);
   if (classMirror.superclass == null) {
     Expect.equals(reflectClass(Object), classMirror);
   } else {
     check(classMirror.superclass);
   }
 }
 
 main() {
   currentMirrorSystem().libraries.values.forEach((libraryMirror) {
     libraryMirror.classes.values.forEach((classMirror) {
       check(classMirror);
     });
   });
 
   Expect.throws(() => reflectClass(dynamic),
                 (e) => e is ArgumentError,
                 'dynamic is not a class');
 }