Always initialize the EventHandler in the standalone.

sdk/lib/io/eventhandler.dart

Index: sdk/lib/io/eventhandler.dart
diff --git a/sdk/lib/io/eventhandler.dart b/sdk/lib/io/eventhandler.dart
index 003c3ed23b9e1811f1576fb9c6afe05e42c56582..376b799cade6fa47cd58e255ff11064e8efff72b 100644
--- a/sdk/lib/io/eventhandler.dart
+++ b/sdk/lib/io/eventhandler.dart
@@ -5,6 +5,7 @@
 part of dart.io;
 
 class _EventHandler {
-  external static void _start();
-  external static _sendData(Object sender, ReceivePort receivePort, int data);
+  external static void _sendData(Object sender,
+                                 ReceivePort receivePort,
+                                 int data);
 }