Migrated test block 17 to Dart 2.0.

tests/corelib/map_values4_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.
-
-import "package:expect/expect.dart";
-
-// Dart2js had a bug where the type information was not set correctly if the
-// generic type of the map was not directly used (but only indirectly through
-// map.values).
-
-main() {
-  var map1 = <int, String>{1: "42", 2: "499"};
-  Expect.isTrue(map1.values is Iterable<String>);
-  Expect.isFalse(map1.values is Iterable<bool>);
-}