Add copyright header to generated analyzer files.

pkg/analyzer/lib/src/generated/engine.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;
 
 import 'java_core.dart';
 import 'java_engine.dart';
 import 'utilities_collection.dart';
 import 'utilities_general.dart';
 import 'instrumentation.dart';
@@ skipping 8051 matching lines @@
 
   void logError3(Exception exception) {
   }
 
   void logInformation(String message) {
   }
 
   void logInformation2(String message, Exception exception) {
   }
 }