Optimize ElementId search, rename the test file.

pkg/analysis_server/test/services/index2/test_all.dart

Index: pkg/analysis_server/test/services/index2/test_all.dart
diff --git a/pkg/analysis_server/test/services/index2/test_all.dart b/pkg/analysis_server/test/services/index2/test_all.dart
index 7219495908bf353e2a50704d7083ee9c03b35763..ebc17d69d509ad86abf7f4689270c18db64987bd 100644
--- a/pkg/analysis_server/test/services/index2/test_all.dart
+++ b/pkg/analysis_server/test/services/index2/test_all.dart
@@ -5,7 +5,7 @@
 import 'package:unittest/unittest.dart';
 
 import '../../utils.dart';
-import 'index2.dart' as index;
+import 'index2_test.dart' as index_test;
 
 /**
  * Utility for manually running all tests.
@@ -13,6 +13,6 @@ import 'index2.dart' as index;
 main() {
   initializeTestEnvironment();
   group('index', () {
-    index.main();
+    index_test.main();
   });
 }