xtime: Add a wrapper for timer_create()/setitimer()

setitimer() is obsolescent in POSIX 2008 and removed from POSIX 2024.
However, at least macOS doesn't implement the new timer_create() API, so
we still need the setitimer() fallback.

1 files changed, 9 insertions, 0 deletions

diff --git a/build/has/timer-create.c b/build/has/timer-create.c
new file mode 100644
index 0000000..d5354c3
--- /dev/null
+++ b/build/has/timer-create.c
@@ -0,0 +1,9 @@
+// Copyright © Tavian Barnes <tavianator@tavianator.com>
+// SPDX-License-Identifier: 0BSD
+
+#include <time.h>
+
+int main(void) {
+	timer_t timer;
+	return timer_create(CLOCK_REALTIME, NULL, &timer);
+}