Language tests updated to use const instead of final.

tests/language/default_init_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.
 
 // Tests static and instance fields initialization.
 class DefaultInitTest {
   static testMain() {
     Expect.equals(0, A.a);
     Expect.equals(2, A.b);
     Expect.equals(null, A.c);
 
     A a1 = new A(42);
     Expect.equals(42, a1.d);
     Expect.equals(null, a1.e);
 
     A a2 = new A.named(43);
     Expect.equals(null, a2.d);
     Expect.equals(43, a2.e);
 
     Expect.equals(42, B.instance.x);
     Expect.equals(3, C.instance.z);
   }
 }
 
 class A {
-  static final int a = 0;
-  static final int b = 2;
+  static const int a = 0;
+  static const int b = 2;
   static int c;
   int d;
   int e;
 
   A(int val) {
     d = val;
   }
 
   A.named(int val) {
     e = val;
   }
 }
 
 // The following tests cover cases described in b/4101270
 
 class B {
-  static final B instance = const B();
+  static const B instance = const B();
   // by putting this field after the static initializer above, the JS code gen
   // was calling the constructor before the setter of this property was defined.
   final int x;
   const B() : this.x = (41 + 1);
 }
 
 class C {
   // forward reference to another class
-  static final D instance = const D();
+  static const D instance = const D();
   C() {}
 }
 
 class D {
   const D(): this.z = 3;
   final int z;
 }
 
 main() {
   DefaultInitTest.testMain();
 }