Revert "Remove Expect from core library."

tests/language/function_type_alias3_test.dart

 // Copyright (c) 2011, 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.
 //
 // Dart test for function type alias with an imported result type that happens
 // to have the same name as a type parameter.
 
 library main;
-import "package:expect/expect.dart";
 import "library11.dart" as lib11;
 
 typedef lib11.Library111<Library111>
     F<Library111>(lib11.Library111<Library111> a, Library111 b);
 
 class A<T> {
   T foo(T a, bool b) {
   }
 }
 
 main() {
   var a = new A<lib11.Library111<bool>>();
   var b = new A<lib11.Library111<int>>();
   Expect.isTrue(a.foo is F);
   Expect.isTrue(a.foo is F<bool>);
   Expect.isTrue(a.foo is !F<int>);
   Expect.isTrue(b.foo is F);
   Expect.isTrue(b.foo is !F<bool>);
   Expect.isTrue(a.foo is !F<int>);
 }