Migrate async tests to strong

tests/lib_strong/async/run_zoned5_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:async_helper/async_helper.dart';
+import "package:expect/expect.dart";
+import 'dart:async';
+
+main() {
+  asyncStart();
+  // Ensure that `runZoned`'s onError handles synchronous errors.
+  runZoned(() { throw 0; },
+           onError: (e) {
+             Expect.equals(0, e);
+             asyncEnd();
+           });
+}