Ticket 48989 - Improve counter overflow fix
    
    Fix Description:
    * load should only be a load, no cmp xchg
    * set can be a store_n, which still is atomic. We don't need cmp xchg
    * Add a cmocka test case of the values
    * remove the sunos asm
    * remove the x86 asm
    
    https://pagure.io/389-ds-base/issue/48989
    
    Author: wibrown
    
    Review by: mreynolds (Thanks!)