Change new List(n) to return fixed length list.

tests/language/gc_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.
 // Testing GC, issue 1469.
 
 
 main() {
   var div;
   for (int i = 0; i < 200; ++i) {
-    List l = new List.fixedLength(1000000);
+    List l = new List(1000000);
     var m  = 2;
     div = (_) {
       var b = l;  // Was causing OutOfMemory.
     };
-    var lSmall = new List.fixedLength(3);
+    var lSmall = new List(3);
     // Circular reference between new and old gen objects.
     lSmall[0] = l;
     l[0] = lSmall;
   }
 }