Migrating another batch of tests to dart 2.

tests/language/closures_initializer_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.
-
-class A<T> {
-  var t;
-  A() : t = (() => new List<T>());
-}
-
-class B<T> {
-  var t;
-  B() : t = (() => T);
-}
-
-expect(result, expected) {
-  if (result != expected) {
-    throw 'Expected $expected, got $result';
-  }
-}
-
-main() {
-  expect(new A<int>().t() is List<int>, true);
-  expect(new A<String>().t() is List<int>, false);
-  expect(new B<int>().t() is Type, true);
-  expect(new B<int>().t(), int);
-}