Migrating another batch of tests to dart 2.

tests/language_strong/closure_with_super_send_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.
-
-import "package:expect/expect.dart";
-
-// Test a closurized super send.
-
-class Super {
-  m() => "super";
-}
-
-class Sub extends Super {
-  m() => "sub";
-
-  test() {
-    var x;
-    [0].forEach((e) => x = super.m());
-    return x;
-  }
-}
-
-main() {
-  Expect.equals("super", new Sub().test());
-  Expect.equals("super", new Super().m());
-  Expect.equals("sub", new Sub().m());
-}