Revert "Remove Expect from core library."

tests/language/generic_syntax_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.
 
-import "package:expect/expect.dart";
-
 // Dart test verifying that the parser does not confuse parameterized types with
 // boolean expressions, since both contain '<'.
 
 class GenericSyntaxTest<B, C, D, E, F> {
   GenericSyntaxTest() {}
 
   void foo(x1, x2, x3, x4, x5) {
     Expect.equals(true, x1);
     Expect.equals(3, x2);
     Expect.equals(4, x3);
@@ skipping 22 matching lines @@
     new GenericSyntaxTest().test();
   }
 }
 
 abstract class A<B, C, D, E, F> {
 }
 
 main() {
   GenericSyntaxTest.testMain();
 }