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

fusl/src/ipc/semctl.c

Index: fusl/src/ipc/semctl.c
diff --git a/fusl/src/ipc/semctl.c b/fusl/src/ipc/semctl.c
new file mode 100644
index 0000000000000000000000000000000000000000..673a9a8c996b2bd18657b1dff7f6934ec34b2d69
--- /dev/null
+++ b/fusl/src/ipc/semctl.c
@@ -0,0 +1,28 @@
+#include <sys/sem.h>
+#include <stdarg.h>
+#include "syscall.h"
+#include "ipc.h"
+
+union semun {
+	int val;
+	struct semid_ds *buf;
+	unsigned short *array;
+};
+
+int semctl(int id, int num, int cmd, ...)
+{
+	union semun arg = {0};
+	va_list ap;
+	switch (cmd) {
+	case SETVAL: case GETALL: case SETALL: case IPC_STAT: case IPC_SET:
+	case IPC_INFO: case SEM_INFO: case SEM_STAT:
+		va_start(ap, cmd);
+		arg = va_arg(ap, union semun);
+		va_end(ap);
+	}
+#ifdef SYS_semctl
+	return syscall(SYS_semctl, id, num, cmd | IPC_64, arg.buf);
+#else
+	return syscall(SYS_ipc, IPCOP_semctl, id, num, cmd | IPC_64, &arg.buf);
+#endif
+}