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

fusl/src/time/timer_gettime.c

Index: fusl/src/time/timer_gettime.c
diff --git a/fusl/src/time/timer_gettime.c b/fusl/src/time/timer_gettime.c
new file mode 100644
index 0000000000000000000000000000000000000000..ed6d8d65ce1ac0b488002e5a9503b1fbd84ddea3
--- /dev/null
+++ b/fusl/src/time/timer_gettime.c
@@ -0,0 +1,12 @@
+#include <time.h>
+#include <limits.h>
+#include "pthread_impl.h"
+
+int timer_gettime(timer_t t, struct itimerspec *val)
+{
+	if ((intptr_t)t < 0) {
+		pthread_t td = (void *)((uintptr_t)t << 1);
+		t = (void *)(uintptr_t)(td->timer_id & INT_MAX);
+	}
+	return syscall(SYS_timer_gettime, t, val);
+}