Add copyright header to generated analyzer files.

pkg/analyzer/lib/src/generated/parser.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.parser;
 
 import 'dart:collection';
 import 'java_core.dart';
 import 'instrumentation.dart';
 import 'error.dart';
 import 'source.dart';
@@ skipping 9285 matching lines @@
       if ("\n" == separator) {
         _writer.print("\n");
         indent();
       } else if (i > 0) {
         _writer.print(separator);
       }
       _writer.print(tokens[i].lexeme);
     }
   }
 }