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

pkg/analyzer/test/generated/test_support.dart

Index: pkg/analyzer/test/generated/test_support.dart
diff --git a/pkg/analyzer/test/generated/test_support.dart b/pkg/analyzer/test/generated/test_support.dart
index 666b233b961bf6cdc7c78f444f1894374c135c9b..6c1b066f4cc47a61c55fd6779606f37258a9131f 100644
--- a/pkg/analyzer/test/generated/test_support.dart
+++ b/pkg/analyzer/test/generated/test_support.dart
@@ -2,9 +2,6 @@
 // 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.test_support;
 
 import 'dart:collection';