Revert "Remove Expect from core library."

tests/standalone/int_array_load_elimination_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.
 //
 // Test correct load elimination for scalar lists.
 
 // TODO: remove once bug 2264 fixed.
 library int_array_load_elimination;
 
-import "package:expect/expect.dart";
 import 'dart:typeddata';
 
 void testUint16() {
   Uint16List intArray = new Uint16List(1);
   intArray[0] = -1;
   var x = intArray[0];
   Expect.equals(65535, x);
 }
 
 main() {
   for (int i = 0; i < 2000; i++) {
     testUint16();
   }
 }