Revert mixin fix r41424 until mirrors issue 21474 is fixed.

tests/language/mixin_type_parameter5_test.dart

Index: tests/language/mixin_type_parameter5_test.dart
===================================================================
--- tests/language/mixin_type_parameter5_test.dart	(revision 41424)
+++ tests/language/mixin_type_parameter5_test.dart	(working copy)
@@ -1,26 +0,0 @@
-// Copyright (c) 2014, 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.
-
-class MixinA<T> {
-  T intField;
-}
-
-class MixinB<S> {
-  S stringField;
-}
-
-class MixinC<U, V> {
-  U listField;
-  V mapField;
-}
-
-class C extends Object with MixinA<int>, MixinB<String>, MixinC<List, Map> {}
-
-void main() {
-  var c = new C();
-  c.intField = 0;
-  c.stringField = '';
-  c.listField = [];
-  c.mapField = {};
-}