Test safe135

PPC safe135
"LwSyncdWW Wse LwSyncdWW Wse"
Cycle=LwSyncdWW Wse LwSyncdWW Wse
Relax=
Safe=Wse LwSyncdWW
{
0:r2=x; 0:r4=y;
1:r2=y; 1:r4=x;
}
 P0           | P1           ;
 li r1,2      | li r1,2      ;
 stw r1,0(r2) | stw r1,0(r2) ;
 lwsync       | lwsync       ;
 li r3,1      | li r3,1      ;
 stw r3,0(r4) | stw r3,0(r4) ;
exists
(x=2 /\ y=2)