add EPOLLWAKEUP flag to sys/epoll.h

include/sys/epoll.h

@@ -28,6 +28,7 @@ enum EPOLL_EVENTS { __EPOLL_DUMMY };
 #define EPOLLERR 0x008
 #define EPOLLHUP 0x010
 #define EPOLLRDHUP 0x2000
+#define EPOLLWAKEUP (1U<<29)
 #define EPOLLONESHOT (1U<<30)
 #define EPOLLET (1U<<31)