Migrate language block 46 - canonical_const ... char_escape.

tests/language_2/canonical_const_test.dart

 // Copyright (c) 2011, 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.
 // Check that initializers of static const fields are compile time constants.
 
 import "package:expect/expect.dart";
 
 class CanonicalConstTest {
   static const A = const C1();
   static const B = const C2();
 
   static testMain() {
     Expect.identical(null, null);
     Expect.isFalse(identical(null, 0));
     Expect.identical(1, 1);
     Expect.isFalse(identical(1, 2));
     Expect.identical(true, true);
     Expect.identical("so", "so");
     Expect.identical(const Object(), const Object());
     Expect.isFalse(identical(const Object(), const C1()));
     Expect.identical(const C1(), const C1());
     Expect.identical(A, const C1());
     Expect.isFalse(identical(const C1(), const C2()));
     Expect.identical(B, const C2());
-    // TODO(johnlenz): these two values don't currently have the same type
-    // Expect.identical(const [1,2], const List[1,2]);
     Expect.isFalse(identical(const [2, 1], const [1, 2]));
     Expect.identical(const <int>[1, 2], const <int>[1, 2]);
     Expect.identical(const <Object>[1, 2], const <Object>[1, 2]);
     Expect.isFalse(identical(const <int>[1, 2], const <double>[1.0, 2.0]));
     Expect.identical(const {"a": 1, "b": 2}, const {"a": 1, "b": 2});
     Expect.isFalse(identical(const {"a": 1, "b": 2}, const {"a": 2, "b": 2}));
   }
 }
 
 class C1 {
   const C1();
 }
 
 class C2 extends C1 {
   const C2() : super();
 }
 
 main() {
   CanonicalConstTest.testMain();
 }