Extract common code, add host IP to --debug and --enable-vm-service options

dart/tests/standalone/vmservice/test_helper.dart

Index: dart/tests/standalone/vmservice/test_helper.dart
diff --git a/dart/tests/standalone/vmservice/test_helper.dart b/dart/tests/standalone/vmservice/test_helper.dart
index 310d2afda24437261a61dc7f221c42dfea8da155..d7c580ec05e4d0f11a998f68117119d3a8eadf15 100644
--- a/dart/tests/standalone/vmservice/test_helper.dart
+++ b/dart/tests/standalone/vmservice/test_helper.dart
@@ -140,9 +140,9 @@ class TestLauncher {
       var first = true;
       process.stdout.transform(UTF8.decoder)
                     .transform(new LineSplitter()).listen((line) {
-        if (line.startsWith('VMService listening on port ')) {
-          RegExp portExp = new RegExp(r"\d+");
-          var port = portExp.stringMatch(line);
+        if (line.startsWith('VMService listening on ')) {
+          RegExp portExp = new RegExp(r"\d+.\d+.\d+.\d+:(\d+)");
+          var port = portExp.firstMatch(line).group(1);
           portNumber = int.parse(port);
         }
         if (line == '') {