stream_file: disable read ahead for remote files on macOS

this can cause stutter on remote files because in certain cases this
causes a reconnect to the remote that leads to the file not being read
fast enough. VLC had the same problem and fixes it the same way.
https://github.com/videolan/vlc/commit/b8b8c438f8f65a93da82364c8fea1dbf987c4a8e

Fixes #4434

stream/stream_file.c

@@ -340,8 +340,15 @@ static int open_f(stream_t *stream, const struct stream_open_args *args)
     stream->get_size = get_size;
     stream->close = s_close;
 
-    if (check_stream_network(p->fd))
+    if (check_stream_network(p->fd)) {
         stream->streaming = true;
+#if HAVE_COCOA
+        if (fcntl(p->fd, F_RDAHEAD, 0) < 0) {
+            MP_VERBOSE(stream, "Cannot disable read ahead on file '%s': %s\n",
+                       filename, mp_strerror(errno));
+        }
+#endif
+    }
 
     p->orig_size = get_size(stream);