Test k3

PPC k3 (KernelThree)
"From Linux Kernel examples, load dependency barrier not needed for PPC"
(* Simplified *)
{
  a=2 ; p = c ; c = 3 ; d=0 ;
  0:r5=a ; 0:r6=p ;
  1:r5=d ; 1:r6=p ;
}
        P0      |       P1    ;
li r1,1         | ld  r1,0,r6 ;
stw r1,0,r5     | lwz r2,0,r1 ;
std r5,0,r6     | stw r2,0,r5 ;

exists (d=2)