Language tests updated to use const instead of final.

tests/language/compile_time_constant_a_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.
 
-final m1 = const { 'a': 400 + 99 };
-final m2 = const { 'a': 499, 'b': 42 };
-final m3 = const { 'm1': m1, 'm2': m2 };
-final m4 = const { 'z': 9, 'a': 8, 'm': 7 };
-final m5 = const { '': 499 };
-final m6 = const { 'a': 499 };
-final m7 = const {};
+const m1 = const { 'a': 400 + 99 };
+const m2 = const { 'a': 499, 'b': 42 };
+const m3 = const { 'm1': m1, 'm2': m2 };
+const m4 = const { 'z': 9, 'a': 8, 'm': 7 };
+const m5 = const { '': 499 };
+const m6 = const { 'a': 499 };
+const m7 = const {};
 
 bool isIllegalAccessException(o) => o is IllegalAccessException;
 
 main() {
   Expect.equals(499, m1['a']);
   Expect.equals(null, m1['b']);
   Expect.listEquals(['a'], m1.getKeys());
   Expect.listEquals([499], m1.getValues());
   Expect.isTrue(m1.containsKey('a'));
   Expect.isFalse(m1.containsKey('toString'));
@@ skipping 95 matching lines @@
   Expect.throws(() => m7.remove('a'), isIllegalAccessException);
   Expect.throws(() => m7.remove('b'), isIllegalAccessException);
   Expect.throws(() => m7.clear(), isIllegalAccessException);
   Expect.throws(() => m7['b'] = 42, isIllegalAccessException);
   Expect.throws(() => m7['a'] = 499, isIllegalAccessException);
   Expect.throws(() => m7.putIfAbsent('a', () => 499),
                 isIllegalAccessException);
   Expect.throws(() => m7.putIfAbsent('z', () => 499),
                 isIllegalAccessException);
 }