Add parser support for covariant parameters

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 278 matching lines @@
   ParserErrorCode.ABSTRACT_STATIC_METHOD,
   ParserErrorCode.ABSTRACT_TOP_LEVEL_FUNCTION,
   ParserErrorCode.ABSTRACT_TOP_LEVEL_VARIABLE,
   ParserErrorCode.ABSTRACT_TYPEDEF,
   ParserErrorCode.ANNOTATION_ON_ENUM_CONSTANT,
   ParserErrorCode.ASYNC_KEYWORD_USED_AS_IDENTIFIER,
   ParserErrorCode.BREAK_OUTSIDE_OF_LOOP,
   ParserErrorCode.CLASS_IN_CLASS,
   ParserErrorCode.COLON_IN_PLACE_OF_IN,
   ParserErrorCode.CONSTRUCTOR_WITH_RETURN_TYPE,
+  ParserErrorCode.CONST_AND_COVARIANT,
   ParserErrorCode.CONST_AND_FINAL,
   ParserErrorCode.CONST_AND_VAR,
   ParserErrorCode.CONST_CLASS,
   ParserErrorCode.CONST_CONSTRUCTOR_WITH_BODY,
   ParserErrorCode.CONST_ENUM,
   ParserErrorCode.CONST_FACTORY,
   ParserErrorCode.CONST_METHOD,
   ParserErrorCode.CONST_TYPEDEF,
   ParserErrorCode.CONTINUE_OUTSIDE_OF_LOOP,
   ParserErrorCode.CONTINUE_WITHOUT_LABEL_IN_CASE,
+  ParserErrorCode.COVARIANT_AFTER_VAR,
+  ParserErrorCode.COVARIANT_AND_STATIC,
+  ParserErrorCode.COVARIANT_CONSTRUCTOR,
+  ParserErrorCode.COVARIANT_TOP_LEVEL_DECLARATION,
   ParserErrorCode.DEFAULT_VALUE_IN_FUNCTION_TYPE,
   ParserErrorCode.DIRECTIVE_AFTER_DECLARATION,
   ParserErrorCode.DUPLICATED_MODIFIER,
   ParserErrorCode.DUPLICATE_LABEL_IN_SWITCH_STATEMENT,
   ParserErrorCode.EMPTY_ENUM_BODY,
   ParserErrorCode.ENUM_IN_CLASS,
   ParserErrorCode.EQUALITY_CANNOT_BE_EQUALITY_OPERAND,
   ParserErrorCode.EXPECTED_CASE_OR_DEFAULT,
   ParserErrorCode.EXPECTED_CLASS_MEMBER,
   ParserErrorCode.EXPECTED_EXECUTABLE,
@@ skipping 11 matching lines @@
   ParserErrorCode.EXTERNAL_FIELD,
   ParserErrorCode.EXTERNAL_GETTER_WITH_BODY,
   ParserErrorCode.EXTERNAL_METHOD_WITH_BODY,
   ParserErrorCode.EXTERNAL_OPERATOR_WITH_BODY,
   ParserErrorCode.EXTERNAL_SETTER_WITH_BODY,
   ParserErrorCode.EXTERNAL_TYPEDEF,
   ParserErrorCode.FACTORY_TOP_LEVEL_DECLARATION,
   ParserErrorCode.FACTORY_WITHOUT_BODY,
   ParserErrorCode.FACTORY_WITH_INITIALIZERS,
   ParserErrorCode.FIELD_INITIALIZER_OUTSIDE_CONSTRUCTOR,
+  ParserErrorCode.FINAL_AND_COVARIANT,
   ParserErrorCode.FINAL_AND_VAR,
   ParserErrorCode.FINAL_CLASS,
   ParserErrorCode.FINAL_CONSTRUCTOR,
   ParserErrorCode.FINAL_ENUM,
   ParserErrorCode.FINAL_METHOD,
   ParserErrorCode.FINAL_TYPEDEF,
   ParserErrorCode.FUNCTION_TYPED_PARAMETER_VAR,
   ParserErrorCode.GETTER_IN_FUNCTION,
   ParserErrorCode.GETTER_WITH_PARAMETERS,
   ParserErrorCode.ILLEGAL_ASSIGNMENT_TO_NON_ASSIGNABLE,
@@ skipping 539 matching lines @@
 
   @override
   int get hashCode => ordinal;
 
   @override
   int compareTo(ErrorProperty other) => ordinal - other.ordinal;
 
   @override
   String toString() => name;
 }