Function pthread_attr_setguardsize 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn pthread_attr_setguardsize(
    attr: *mut pthread_attr_t,
    guardsize: c_int,
) -> c_int

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