Migrating block 50, first commit, after tool has run

tests/language/compile_time_constant_l_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";
-
-class A {
-  final x;
-  const A([x = 499]) : this.x = x;
-}
-
-class B extends A {
-  const B();
-  final z = 99;
-}
-
-class C extends B {
-  const C(this.y);
-  final y;
-}
-
-const v = const C(42);
-
-main() {
-  Expect.equals(42, v.y);
-  Expect.equals(499, v.x);
-  Expect.equals(99, v.z);
-}