Deprecate the generated AST library and clean up imports

pkg/analysis_server/test/services/correction/status_test.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 test.services.correction.status;
 
 import 'package:analysis_server/src/protocol_server.dart' hide Element;
 import 'package:analysis_server/src/services/correction/source_range.dart';
 import 'package:analysis_server/src/services/correction/status.dart';
 import 'package:analysis_server/src/services/search/search_engine.dart';
+import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
-import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 import 'package:unittest/unittest.dart';
 
 import '../../abstract_single_unit.dart';
 import '../../utils.dart';
 
 main() {
   initializeTestEnvironment();
   defineReflectiveTests(RefactoringLocationTest);
@@ skipping 202 matching lines @@
     expect(refactoringStatus.severity, RefactoringProblemSeverity.FATAL);
     expect(refactoringStatus.message, 'msg');
   }
 
   void test_newWarning() {
     RefactoringStatus refactoringStatus = new RefactoringStatus.warning('msg');
     expect(refactoringStatus.severity, RefactoringProblemSeverity.WARNING);
     expect(refactoringStatus.message, 'msg');
   }
 }