Fix crash that happens when we send an object whose type is in a defer

tests/isolate/issue_21398_parent_isolate2_test.dart

+// Copyright (c) 2015, 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 'dart:isolate';
+import 'dart:async';
+import "package:expect/expect.dart";
+
+import "deferred_loaded_lib.dart" deferred as lib;
+
+// In this test case we send an object created from a deferred library
+// that is loaded in the child isolate but not the parent isolate. The
+// parent isolate does not know about the type of this object and throws
+// an unhandled exception.
+funcChild(args) {
+  var replyPort = args[0];
+  // Deferred load a library, create an object from that library and send
+  // it over to the parent isolate which has not yet loaded that library.
+  lib.loadLibrary().then((_) {
+    replyPort.send(new lib.FromChildIsolate());
+  });
+}
+
+void helperFunction() {
+  var receivePort = new ReceivePort();
+
+  // Spawn an isolate using spawnFunction.
+  Isolate.spawn(funcChild, [receivePort.sendPort]).then(
+    (isolate) {
+      receivePort.listen(
+        (msg) {
+          // We don't expect to receive any valid messages.
+          Expect.fail("We don't expect to receive any valid messages");
+          receivePort.close();
+        },
+        onError: (e) {
+          // We don't expect to receive any error messages, per spec listen
+          // does not receive an error object.
+          Expect.fail("We don't expect to receive any error messages");
+          receivePort.close();
+        }
+      );
+    }
+  );
+}
+
+main() {
+  helperFunction(); /// 01: runtime error

[ahe, 2017/04/06 15:38:18]

Why is this a multi-test?

[siva, 2017/04/06 18:15:42]

It doesn't have to be, I think I did this way so it was not necessary to add a
line in the status file stating a RuntimeError is expected.

[ahe, 2017/04/07 06:14:17]

Which runtime error is expected, the one one line 33, line 39, or something
different?

+}