Remove deprecated Expect from the libraries.

tests/language/deopt_hoisted_smi_check_vm_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.
 // Test deoptimization on an optimistically hoisted smi check.
 
+import 'package:expect/expect.dart';
+
 sum(a, b) {
   var sum = 0;
   for (var j = 1; j < 10; j++) {
     for (var i = a; i < b; i++) {
       sum++;
     }
   }
   return sum;
 }
 
 mask(x) {
   for (var i = 0; i < 10; i++) {
     if (i == 1) {
       return x;
     }
     x = x & 0xFF;
   }
 }
 
 main() {
   for (var i = 0; i < 2000; i++) {
     Expect.equals(9, sum(1, 2));
     Expect.equals(0xAB, mask(0xAB));
   }
   Expect.equals(9, sum(1.0, 2.0));  // Passing double causes deoptimization.
   Expect.equals(0xAB, mask(0x1000000AB));
 }