[core] omit fdevent select() code if poll() avail

omit fdevent select() code if poll() avail
translate server.event-handler = "select" to "poll" when poll available

src/fdevent.c

@@ -61,6 +61,10 @@ int fdevent_config(const char **event_handler_name, log_error_st *errh) {
 	if (NULL != event_handler && 0 == strcmp(event_handler, "libev"))
 		event_handler = NULL;
 #endif
+#ifdef FDEVENT_USE_POLL
+	if (NULL != event_handler && 0 == strcmp(event_handler, "select"))
+		event_handler = "poll";
+#endif
 
 	if (NULL == event_handler) {
 		/* choose a good default

src/fdevent_impl.h

@@ -16,6 +16,7 @@ struct epoll_event;     /* declaration */
 struct pollfd;          /* declaration */
 #endif
 
+#ifndef FDEVENT_USE_POLL
 #if defined HAVE_SELECT
 # ifdef __WIN32
 #  include <winsock2.h>
@@ -25,6 +26,7 @@ struct pollfd;          /* declaration */
 #  include <sys/select.h>
 # endif
 #endif
+#endif
 
 #if defined HAVE_SYS_DEVPOLL_H && defined(__sun)
 # define FDEVENT_USE_SOLARIS_DEVPOLL