Add a "fork" of musl as //fusl.

fusl/src/ipc/semtimedop.c

Index: fusl/src/ipc/semtimedop.c
diff --git a/fusl/src/ipc/semtimedop.c b/fusl/src/ipc/semtimedop.c
new file mode 100644
index 0000000000000000000000000000000000000000..b0c4cf9f82a79cd8b532c19246d7b315fac91b3e
--- /dev/null
+++ b/fusl/src/ipc/semtimedop.c
@@ -0,0 +1,13 @@
+#define _GNU_SOURCE
+#include <sys/sem.h>
+#include "syscall.h"
+#include "ipc.h"
+
+int semtimedop(int id, struct sembuf *buf, size_t n, const struct timespec *ts)
+{
+#ifdef SYS_semtimedop
+	return syscall(SYS_semtimedop, id, buf, n, ts);
+#else
+	return syscall(SYS_ipc, IPCOP_semtimedop, id, n, 0, buf, ts);
+#endif
+}