5042 stop using deprecated atomic functions

*** 838,848 ****
                   */
                  curthread->t_red_pp = red_pp;
  
                  atomic_add_32(&red_nmapped, 1);
                  while (fp - (uintptr_t)curthread->t_stkbase < red_closest) {
!                         (void) cas32(&red_closest, red_closest,
                              (uint32_t)(fp - (uintptr_t)curthread->t_stkbase));
                  }
                  return (1);
          }
  
--- 838,848 ----
                   */
                  curthread->t_red_pp = red_pp;
  
                  atomic_add_32(&red_nmapped, 1);
                  while (fp - (uintptr_t)curthread->t_stkbase < red_closest) {
!                         (void) atomic_cas_32(&red_closest, red_closest,
                              (uint32_t)(fp - (uintptr_t)curthread->t_stkbase));
                  }
                  return (1);
          }