Store the covariant keyword flag for parameters and fields into Kernel and resynthesize in analyzer.

pkg/analyzer/test/src/summary/resynthesize_kernel_test.dart

 // Copyright (c) 2017, 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.test.src.summary.resynthesize_kernel_test;
 
 import 'dart:async';
 
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
@@ skipping 369 matching lines @@
   test_exportImport_configurations_useDefault() async {
     await super.test_exportImport_configurations_useDefault();
   }
 
   @failingTest
   test_exportImport_configurations_useFirst() async {
     await super.test_exportImport_configurations_useFirst();
   }
 
   @failingTest
-  test_field_covariant() async {
-    await super.test_field_covariant();
-  }
-
-  @failingTest
   test_field_propagatedType_final_dep_inLib() async {
     await super.test_field_propagatedType_final_dep_inLib();
   }
 
   @failingTest
   test_field_propagatedType_final_dep_inPart() async {
     await super.test_field_propagatedType_final_dep_inPart();
   }
 
   @failingTest
@@ skipping 257 matching lines @@
   test_parameter_checked() async {
     await super.test_parameter_checked();
   }
 
   @failingTest
   test_parameter_checked_inherited() async {
     await super.test_parameter_checked_inherited();
   }
 
   @failingTest
-  test_parameter_covariant() async {
-    await super.test_parameter_covariant();
-  }
-
-  @failingTest
   test_parameter_covariant_inherited() async {
     await super.test_parameter_covariant_inherited();
   }
 
   @failingTest
   test_parts_invalidUri() async {
     await super.test_parts_invalidUri();
   }
 
   @failingTest
   test_parts_invalidUri_nullStringValue() async {
     await super.test_parts_invalidUri_nullStringValue();
   }
 
   @failingTest
-  test_setter_covariant() async {
-    await super.test_setter_covariant();
-  }
-
-  @failingTest
   test_syntheticFunctionType_genericClosure() async {
     await super.test_syntheticFunctionType_genericClosure();
   }
 
   @failingTest
   test_syntheticFunctionType_inGenericClass() async {
     await super.test_syntheticFunctionType_inGenericClass();
   }
 
   @failingTest
@@ skipping 215 matching lines @@
   @override
   Future<List<int>> readAsBytes() async {
     return file.readAsBytesSync();
   }
 
   @override
   Future<String> readAsString() async {
     return file.readAsStringSync();
   }
 }