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

fusl/include/aio.h

+#ifndef _AIO_H
+#define _AIO_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <features.h>
+#include <signal.h>
+#include <time.h>
+
+#define __NEED_ssize_t
+#define __NEED_off_t
+
+#include <bits/alltypes.h>
+
+struct aiocb {
+        int aio_fildes, aio_lio_opcode, aio_reqprio;
+        volatile void *aio_buf;
+        size_t aio_nbytes;
+        struct sigevent aio_sigevent;
+        void *__td;
+        int __lock[2];
+        volatile int __err;
+        ssize_t __ret;
+        off_t aio_offset;
+        void *__next, *__prev;
+        char __dummy4[32-2*sizeof(void *)];
+};
+
+#define AIO_CANCELED 0
+#define AIO_NOTCANCELED 1
+#define AIO_ALLDONE 2
+
+#define LIO_READ 0
+#define LIO_WRITE 1
+#define LIO_NOP 2
+
+#define LIO_WAIT 0
+#define LIO_NOWAIT 1
+
+int aio_read(struct aiocb *);
+int aio_write(struct aiocb *);
+int aio_error(const struct aiocb *);
+ssize_t aio_return(struct aiocb *);
+int aio_cancel(int, struct aiocb *);
+int aio_suspend(const struct aiocb *const [], int, const struct timespec *);
+int aio_fsync(int, struct aiocb *);
+
+int lio_listio(int, struct aiocb *__restrict const *__restrict, int, struct sigevent *__restrict);
+
+#if defined(_LARGEFILE64_SOURCE) || defined(_GNU_SOURCE)
+#define aiocb64 aiocb
+#define aio_read64 aio_read
+#define aio_write64 aio_write
+#define aio_error64 aio_error
+#define aio_return64 aio_return
+#define aio_cancel64 aio_cancel
+#define aio_suspend64 aio_suspend
+#define aio_fsync64 aio_fsync
+#define lio_listio64 lio_listio
+#define off64_t off_t
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif