Fix some tests.

tests/compiler/dart2js/simple_inferrer_and_or_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.
 
+import 'package:expect/expect.dart';
 import 'compiler_helper.dart';
 
 const String TEST = """
 class X {}
 returnDyn1() {
   var a;
   ((a = 52) == true) || ((a = 'foo') == true);
   return a;
 }
 
@@ skipping 52 matching lines @@
   var subclassOfInterceptor =
       findTypeMask(compiler, 'Interceptor', 'nonNullSubclass');
 
   checkReturn('returnDyn1', subclassOfInterceptor);
   checkReturn('returnDyn2', subclassOfInterceptor);
   checkReturn('returnDyn3', subclassOfInterceptor);
   checkReturn('returnDyn4', typesInferrer.dynamicType);
   checkReturn('returnDyn5', typesInferrer.dynamicType);
   checkReturn('returnDyn6', typesInferrer.dynamicType);
 }