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

tests/corelib/list_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.
 
 class ListTest {
 
   static testMain() {
     testList();
     testExpandableList();
   }
@@ skipping 31 matching lines @@
     testSomeFirst(val) { return val == 0; }
     test = list.any(testSomeFirst);
     Expect.equals(true, test);
 
     testSomeLast(val) { return val == (list.length - 1); }
     test = list.any(testSomeLast);
     Expect.equals(true, test);
   }
 
   static void testList() {
-    List list = new List.fixedLength(4);
+    List list = new List(4);
     Expect.equals(list.length, 4);
     list[0] = 4;
     expectValues(list, 4, null, null, null);
     String val = "fisk";
     list[1] = val;
     expectValues(list, 4, val, null, null);
     double d = 2.0;
     list[3] = d;
     expectValues(list, 4, val, null, d);
 
@@ skipping 80 matching lines @@
   }
 }
 
 class Yes {
   operator ==(var other) => true;
 }
 
 main() {
   ListTest.testMain();
 }