Epoll event engine is missing EPOLLRDHUP

[michaeltalyansky]

This causes CLOSE_WAIT-state sockets to linger. This fix cures it:

@@ -142,7 +142,7 @@ static __thread struct _st_epolldata {
#define _ST_EPOLL_EXCEP_CNT(fd) (_st_epoll_data->fd_data[fd].ex_ref_cnt)
#define _ST_EPOLL_REVENTS(fd) (_st_epoll_data->fd_data[fd].revents)

-#define _ST_EPOLL_READ_BIT(fd) (_ST_EPOLL_READ_CNT(fd) ? EPOLLIN : 0)
+#define _ST_EPOLL_READ_BIT(fd) (_ST_EPOLL_READ_CNT(fd) ? (EPOLLIN|EPOLLRDHUP) : 0)
#define _ST_EPOLL_WRITE_BIT(fd) (_ST_EPOLL_WRITE_CNT(fd) ? EPOLLOUT : 0)
#define _ST_EPOLL_EXCEP_BIT(fd) (_ST_EPOLL_EXCEP_CNT(fd) ? EPOLLPRI : 0)
#define _ST_EPOLL_EVENTS(fd) \

commit accd04f in my fork.