Pull in test_reflective_loader 0.0.4 and switch analyzer to it.

pkg/analyzer/test/src/util/asserts_test.dart

 // Copyright (c) 2015, 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.
 
 library analyzer.test.src.util.asserts_test;
 
 import 'package:analyzer/src/util/asserts.dart';
+import 'package:test_reflective_loader/test_reflective_loader.dart';
 import 'package:unittest/unittest.dart';
 
-import '../../reflective_tests.dart';
 import '../../utils.dart';
 
 main() {
   initializeTestEnvironment();
-  runReflectiveTests(AnalysisTaskTest);
+  defineReflectiveTests(AnalysisTaskTest);
 }
 
 @reflectiveTest
 class AnalysisTaskTest {
   void test_notNull_notNull() {
     notNull(this);
   }
 
   void test_notNull_null_hasDescription() {
     expect(() => notNull(null, 'desc'), throwsArgumentError);
   }
 
   void test_notNull_null_noDescription() {
     expect(() => notNull(null), throwsArgumentError);
   }
 }