Support enum keys in maps in messages.

tests/isolate/message_enum_test.dart

+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file

[siva, 2015/03/05 23:42:07]

A new file so use 2015.

[koda, 2015/03/06 01:43:04]

I actually wrote it in 2014 :)

+// 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.
+
+// SharedOptions=--enable-enum
+
+import 'package:expect/expect.dart';
+import "dart:isolate";
+
+enum Foo { BAR, BAZ }
+
+main() {
+  var p;
+  p = new RawReceivePort((map) {
+    Expect.equals(1, map.keys.length);
+    Expect.equals(42, map.values.first);
+    var key = map.keys.first;
+    Expect.equals(42, map[key]);
+    p.close();
+  });
+  Isolate.spawn(sendIt, p.sendPort);
+}
+
+void sendIt(port) {
+  var map = { Foo.BAR: 42 };
+  port.send(map);
+}