Ticket 49486 - change ns stress core to use absolute int width.
Bug Description: On some platforms the int width detection does
not correctly function and may cause inconsistent results with
__atomic family instructions.
Fix Description: Convert the un-sized atomic calls in ns
stress core to _8 byte width.
https://pagure.io/389-ds-base/issue/49486
Author: wibrown
Review by: vashirov, lkrispen (Thanks!)