Move constant implementation out of generated

pkg/analyzer/test/src/dart/test_all.dart

 // Copyright (c) 2014, 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.dart.test_all;
 
 import 'package:unittest/unittest.dart';
 
 import '../../utils.dart';
+import 'ast/test_all.dart' as ast;
+import 'constant/test_all.dart' as constant;
 import 'element/test_all.dart' as element;
 
 /// Utility for manually running all tests.
 main() {
   initializeTestEnvironment();
   group('dart tests', () {
+    ast.main();
+    constant.main();
     element.main();
   });
 }