[analyzer] remove "auto-generated do not edit" comments

pkg/analyzer/lib/src/generated/testing/ast_factory.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.
 
-// This code was auto-generated, is not intended to be edited, and is subject to
-// significant change. Please see the README file for more information.
-
 library engine.testing.ast_factory;
 
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/scanner.dart';
 import 'package:analyzer/src/generated/testing/token_factory.dart';
 import 'package:analyzer/src/generated/utilities_dart.dart';
 
 /**
  * The class `AstFactory` defines utility methods that can be used to create AST nodes. The
@@ skipping 955 matching lines @@
       new YieldStatement(
           TokenFactory.tokenFromTypeAndString(TokenType.IDENTIFIER, "yield"),
           TokenFactory.tokenFromType(TokenType.STAR), expression,
           TokenFactory.tokenFromType(TokenType.SEMICOLON));
 
   static YieldStatement yieldStatement(
       Expression expression) => new YieldStatement(
       TokenFactory.tokenFromTypeAndString(TokenType.IDENTIFIER, "yield"), null,
       expression, TokenFactory.tokenFromType(TokenType.SEMICOLON));
 }