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

fusl/src/time/clock_getcpuclockid.c

Index: fusl/src/time/clock_getcpuclockid.c
diff --git a/fusl/src/time/clock_getcpuclockid.c b/fusl/src/time/clock_getcpuclockid.c
new file mode 100644
index 0000000000000000000000000000000000000000..8a0e2d4c3a622f9e8cf11c0cf7300eb1f59b9ea6
--- /dev/null
+++ b/fusl/src/time/clock_getcpuclockid.c
@@ -0,0 +1,14 @@
+#include <time.h>
+#include <errno.h>
+#include <unistd.h>
+#include "syscall.h"
+
+int clock_getcpuclockid(pid_t pid, clockid_t *clk)
+{
+	struct timespec ts;
+	clockid_t id = (-pid-1)*8U + 2;
+	int ret = __syscall(SYS_clock_getres, id, &ts);
+	if (ret) return -ret;
+	*clk = id;
+	return 0;
+}