Remove/skip invalid mirror tests.

tests/lib/mirrors/hierarchy_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 hierarchy_test;
-
-@MirrorsUsed(targets: 'hierarchy_test, Object')
-import 'dart:mirrors';
-
-import 'package:expect/expect.dart';
-
-class FooMixin {
-  foo() => print('foo');
-}
-
-class Qux {
-  qux() => print('qux');
-}
-
-class Bar extends Qux implements FooMixin {
-  bar() => print('bar');
-  foo() => print('foo');
-}
-
-class Baz extends Qux with FooMixin {
-  bar() => print('bar');
-}
-
-stringifyHierarchy(mirror) {
-  var sb = new StringBuffer();
-  for (var type = mirror.type; type != null; type = type.superclass) {
-    sb.write('> ${MirrorSystem.getName(type.qualifiedName)}\n');
-    for (var i in type.superinterfaces) {
-      sb.write('  + ${MirrorSystem.getName(i.qualifiedName)}\n');
-    }
-  }
-  return '$sb';
-}
-
-main() {
-  Expect.stringEquals('''
-> hierarchy_test.Bar
-  + hierarchy_test.FooMixin
-> hierarchy_test.Qux
-> dart.core.Object
-''', stringifyHierarchy(reflect(new Bar()..foo()..bar()..qux())));
-
-  Expect.stringEquals('''
-> hierarchy_test.Baz
-> hierarchy_test.Qux with hierarchy_test.FooMixin
-  + hierarchy_test.FooMixin
-> hierarchy_test.Qux
-> dart.core.Object
-''', stringifyHierarchy(reflect(new Baz()..foo()..bar()..qux())));
-}