Fix the generic type of Map.values for map literals.

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>);
+}