Language tests updated to use const instead of final.

tests/language/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.
 
 class CanonicalConstTest {
-  static final A = const C1();
-  static final B = const C2();
+  static const A = const C1();
+  static const B = const C2();
 
   static testMain() {
     Expect.isTrue(null===null);
     Expect.isTrue(null!==0);
     Expect.isTrue(1===1);
     Expect.isTrue(1!==2);
     Expect.isTrue(true===true);
     Expect.isTrue("so"==="so");
     Expect.isTrue(const Object()===const Object());
     Expect.isTrue(const Object()!==const C1());
@@ skipping 16 matching lines @@
   const C1();
 }
 
 class C2 extends C1 {
   const C2() : super();
 }
 
 main() {
   CanonicalConstTest.testMain();
 }