implement atomic_{cas,swap}_{uint,long,ptr) and atomic_{add,sub}_{int,long}
implement atomic_{cas,swap}_{uint,long,ptr) and atomic_{add,sub}_{int,long}

fixes from and ok miod@

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars