tests: fix build on systems that lack O_CLOEXEC definition
* tests/epoll_create1.c (main): Check that O_CLOEXEC is defined.
* tests/eventfd.c (main): Likewise.
* tests/signalfd.c (main): Likewise.
diff --git a/tests/signalfd.c b/tests/signalfd.c
index 9d4cc98..1b6cd0c 100644
--- a/tests/signalfd.c
+++ b/tests/signalfd.c
@@ -12,7 +12,7 @@
int
main(void)
{
-#if defined HAVE_SYS_SIGNALFD_H && defined HAVE_SIGNALFD
+#if defined HAVE_SYS_SIGNALFD_H && defined HAVE_SIGNALFD && defined O_CLOEXEC
sigset_t mask;
sigemptyset(&mask);
sigaddset(&mask, SIGUSR2);