Raise an exception instead of crashing when attempting to pass a MirrorReference between isolates.

tests/isolate/illegal_msg_test.dart

-// Copyright (c) 2012, 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 illegal_msg_tests;
-import "package:expect/expect.dart";
-import 'dart:isolate';
-import "package:async_helper/async_helper.dart";
-
-funcFoo(x) => x + 2;
-
-echo(sendPort) {
-  var port = new ReceivePort();
-  sendPort.send(port.sendPort);
-  port.listen((msg) {
-    sendPort.send("echoing ${msg(1)}}");
-  });
-}
-
-main() {
-  ReceivePort port = new ReceivePort();
-  Future spawn = Isolate.spawn(echo, port.sendPort);
-  var caught_exception = false;
-  var stream = port.asBroadcastStream();
-  asyncStart();
-  stream.first.then((snd) {
-    try {
-      snd.send(funcFoo);
-    } catch (e) {
-      caught_exception = true;
-    }
-
-    if (caught_exception) {
-      port.close();
-    } else {
-      asyncStart();
-      stream.first.then((msg) {
-        print("from worker ${msg}");
-        asyncEnd();
-      });
-    }
-    Expect.isTrue(caught_exception);
-    asyncEnd();
-  });
-}