Add copyright header to generated analyzer files.

pkg/analyzer/lib/src/generated/error.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.error;
 
 import 'java_core.dart';
 import 'source.dart';
 import 'scanner.dart' show Token;
 import 'ast.dart' show ASTNode;
 import 'element.dart' show Element;
@@ skipping 3621 matching lines @@
   StaticTypeWarningCode.con2(String name, int ordinal, this.message, String correction) : super(name, ordinal) {
     this.correction7 = correction;
   }
 
   String get correction => correction7;
 
   ErrorSeverity get errorSeverity => ErrorType.STATIC_TYPE_WARNING.severity;
 
   ErrorType get type => ErrorType.STATIC_TYPE_WARNING;
 }