ntdll: Avoid inter-process APCs when called for the process itself.
diff --git a/server/protocol.def b/server/protocol.def
index af9db7b..72157fd 100644
--- a/server/protocol.def
+++ b/server/protocol.def
@@ -635,6 +635,7 @@
     apc_call_t   call;         /* call arguments */
 @REPLY
     obj_handle_t handle;       /* APC handle */
+    int          self;         /* run APC in caller itself? */
 @END