Revert "Remove Expect from core library."

tests/lib/scalarlist/float32x4_test.dart

 // Copyright (c) 2013, 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.
 
 // Library tag to be able to run in html test framework.
 library float32x4_test;
 
-import "package:expect/expect.dart";
 import 'dart:scalarlist';
 
 testAdd() {
   var m = new Float32x4(-1.0, -2.0, -3.0, -4.0);
   var n = new Float32x4(1.0, 2.0, 3.0, 4.0);
   var o = m + n;
   Expect.equals(0.0, o.x);
   Expect.equals(0.0, o.y);
   Expect.equals(0.0, o.z);
   Expect.equals(0.0, o.w);
@@ skipping 348 matching lines @@
     testScale();
     testClamp();
     testAbs();
     testMin();
     testMax();
     testSqrt();
     testReciprocal();
     testReciprocalSqrt();
   }
 }