Make dartk-{release,debug} builders work properly again

utils/kernel-service/kernel-service.dart

Index: utils/kernel-service/kernel-service.dart
diff --git a/utils/kernel-service/kernel-service.dart b/utils/kernel-service/kernel-service.dart
index b52dcaee67d3cffa366f6a7eb93141793ca93f21..d162465e1d38c77aa5afe69334b48f42c2b83ac8 100644
--- a/utils/kernel-service/kernel-service.dart
+++ b/utils/kernel-service/kernel-service.dart
@@ -327,7 +327,7 @@ Future<CompilationResult> requestParse(
 
 void startBatchServer() {
   final loader = new DartLoaderBatch();
-  HttpServer.bind(InternetAddress.LOOPBACK_IP_V6, workerPort).then((server) {
+  HttpServer.bind('localhost', workerPort).then((server) {
     print('READY ${server.port}');
     server.listen((HttpRequest request) async {
       final rq = JSON.decode(await UTF8.decodeStream(request));