Revert "Remove Expect from core library."

pkg/fixnum/test/int_64_vm_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.
 
 // A test to compare the results of the fixnum library with the Dart VM
 
 library int64vmtest;
-import "package:expect/expect.dart";
 import 'dart:math' as math;
 
 part '../lib/src/int32.dart';
 part '../lib/src/int64.dart';
 part '../lib/src/intx.dart';
 
 final random = new math.Random();
 
 void main() {
   int64VMTest test = new int64VMTest();
@@ skipping 302 matching lines @@
       }
     }
     for (int i = 0; i < RANDOM_TESTS; i++) {
       int64 randomLong = _randomInt64();
       for (int shift = -64; shift <= 64; shift++) {
         _doTestShift(op, randomLong, shift);
       }
     }
   }
 }