Add missed error code

pkg/analyzer/lib/error/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.
 
 library analyzer.error.error;
 
 import 'dart:collection';
 
 import 'package:analyzer/error/listener.dart';
 import 'package:analyzer/src/dart/scanner/scanner.dart' show ScannerErrorCode;
@@ skipping 131 matching lines @@
   CompileTimeErrorCode.INVALID_CONSTANT,
   CompileTimeErrorCode.INVALID_CONSTRUCTOR_NAME,
   CompileTimeErrorCode.INVALID_FACTORY_NAME_NOT_A_CLASS,
   CompileTimeErrorCode.INVALID_IDENTIFIER_IN_ASYNC,
   CompileTimeErrorCode.INVALID_MODIFIER_ON_CONSTRUCTOR,
   CompileTimeErrorCode.INVALID_MODIFIER_ON_SETTER,
   CompileTimeErrorCode.INVALID_REFERENCE_TO_THIS,
   CompileTimeErrorCode.INVALID_TYPE_ARGUMENT_IN_CONST_LIST,
   CompileTimeErrorCode.INVALID_TYPE_ARGUMENT_IN_CONST_MAP,
   CompileTimeErrorCode.INVALID_URI,
+  CompileTimeErrorCode.INVALID_USE_OF_COVARIANT,
   CompileTimeErrorCode.LABEL_IN_OUTER_SCOPE,
   CompileTimeErrorCode.LABEL_UNDEFINED,
   CompileTimeErrorCode.MEMBER_WITH_CLASS_NAME,
   CompileTimeErrorCode.METHOD_AND_GETTER_WITH_SAME_NAME,
   CompileTimeErrorCode.MISSING_CONST_IN_LIST_LITERAL,
   CompileTimeErrorCode.MISSING_CONST_IN_MAP_LITERAL,
   CompileTimeErrorCode.MIXIN_DECLARES_CONSTRUCTOR,
   CompileTimeErrorCode.MIXIN_DEFERRED_CLASS,
   CompileTimeErrorCode.MIXIN_HAS_NO_CONSTRUCTORS,
   CompileTimeErrorCode.MIXIN_INHERITS_FROM_NOT_OBJECT,
@@ skipping 734 matching lines @@
 
   @override
   int get hashCode => ordinal;
 
   @override
   int compareTo(ErrorProperty other) => ordinal - other.ordinal;
 
   @override
   String toString() => name;
 }