Add an integration test for diagnostics.getDiagnostics.

pkg/analysis_server/test/integration/test_all.dart

Index: pkg/analysis_server/test/integration/test_all.dart
diff --git a/pkg/analysis_server/test/integration/test_all.dart b/pkg/analysis_server/test/integration/test_all.dart
index 8e0c603d4aef10362580574e06b278a6a696bfdb..69ba9bcccc2d412bd103800bae935c5cfef3294d 100644
--- a/pkg/analysis_server/test/integration/test_all.dart
+++ b/pkg/analysis_server/test/integration/test_all.dart
@@ -9,6 +9,7 @@ import 'package:test_reflective_loader/test_reflective_loader.dart';
 import 'analysis/test_all.dart' as analysis_test_all;
 import 'completion/test_all.dart' as completion_test_all;
 import 'coverage_test.dart' as coverage_test;
+import 'diagnostic/test_all.dart' as diagnostic_test_all;
 import 'execution/test_all.dart' as execution_test_all;
 import 'search/test_all.dart' as search_test_all;
 import 'server/test_all.dart' as server_test_all;
@@ -20,6 +21,7 @@ main() {
   defineReflectiveSuite(() {
     analysis_test_all.main();
     completion_test_all.main();
+    diagnostic_test_all.main();
     execution_test_all.main();
     search_test_all.main();
     server_test_all.main();