Support for 64bit statfs on macOS

[ohayetechnology]

With very big filesystems (~1PB) on macOS, we noticed that bindfs returns zero bytes available. This renders most applications unusable.

Good news is a fix appears to be trivial.

static int bindfs_statfs_x(const char *path, struct statfs *stbuf);

#if __APPLE__
    static int bindfs_statfs_x(const char *path, struct statfs *stbuf)
    {
        int res;
        char *real_path;

        real_path = process_path(path, true);
        if (real_path == NULL)
            return -errno;

        res = statfs(real_path, stbuf);
        free(real_path);
        if (res == -1)
            return -errno;

        return 0;
    }
#endif

#ifdef __APPLE__
    .statfs_x = bindfs_statfs_x,
#endif

[mpartel]

Thanks! Released as 1.17.3.