Allow arguments to main.

sdk/lib/_internal/lib/isolate_helper.dart

Index: sdk/lib/_internal/lib/isolate_helper.dart
diff --git a/sdk/lib/_internal/lib/isolate_helper.dart b/sdk/lib/_internal/lib/isolate_helper.dart
index 833fef28b85e623a392fd04ca3ff23c82cab9903..27a51d525f0c7a37a7bebbe173ffba516fc46046 100644
--- a/sdk/lib/_internal/lib/isolate_helper.dart
+++ b/sdk/lib/_internal/lib/isolate_helper.dart
@@ -58,7 +58,13 @@ void startRootIsolate(entry) {
   // by having a "default" isolate (the first one created).
   _globalState.currentContext = rootContext;
 
-  rootContext.eval(entry);
+  if (entry is _MainFunctionArgs) {
+    rootContext.eval(() { entry([]); });
+  } else if (entry is _MainFunctionArgsMessage) {
+    rootContext.eval(() { entry([], null); });
+  } else {
+    rootContext.eval(entry);
+  }
   _globalState.topEventLoop.run();
 }