Fix FunctionTypeAliasElementImpl.visitChildren() for type parameters.

pkg/analyzer/test/generated/compile_time_error_code_driver_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.
 
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import 'compile_time_error_code_test.dart';
 
 main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(CompileTimeErrorCodeTest_Driver);
   });
 }
 
 @reflectiveTest
 class CompileTimeErrorCodeTest_Driver extends CompileTimeErrorCodeTest {
   @override
   bool get enableNewAnalysisDriver => true;
 
   @failingTest
   @override
-  test_typeAliasCannotReferenceItself_typeVariableBounds() {
-    return super.test_typeAliasCannotReferenceItself_typeVariableBounds();
-  }
-
-  @failingTest
-  @override
   test_uriDoesNotExist_import_appears_after_deleting_target() {
     return super.test_uriDoesNotExist_import_appears_after_deleting_target();
   }
 }