Function linkat 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn linkat(
    fd1: c_int,
    path1: *const c_char,
    fd2: c_int,
    path2: *const c_char,
    flags: c_int,
) -> c_int

See https://pubs.opengroup.org/onlinepubs/9799919799/functions/linkat.html.