Pull in test_reflective_loader 0.0.4 and switch analyzer to it.

pkg/analyzer/test/source/package_map_provider_test.dart

Index: pkg/analyzer/test/source/package_map_provider_test.dart
diff --git a/pkg/analyzer/test/source/package_map_provider_test.dart b/pkg/analyzer/test/source/package_map_provider_test.dart
index bb0e1421ea4aedd0201a61c32788bc7364f0ce96..23b8511fc510241c39106b4669bfcc6f9a5a6664 100644
--- a/pkg/analyzer/test/source/package_map_provider_test.dart
+++ b/pkg/analyzer/test/source/package_map_provider_test.dart
@@ -10,14 +10,14 @@ import 'package:analyzer/source/package_map_provider.dart';
 import 'package:analyzer/source/pub_package_map_provider.dart';
 import 'package:analyzer/src/dart/sdk/sdk.dart';
 import 'package:analyzer/src/generated/sdk.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(PubPackageMapProviderTest);
+  defineReflectiveTests(PubPackageMapProviderTest);
 }
 
 @reflectiveTest