Test ppo5

PPC ppo5 (PPCPPOFive)
"is WR to same location in ppo?, intervening write variation"
{
0:r6=x; 0:r7=y; 0:r8=z;
1:r7=y; 1:r8=z;
2:r6=x;
}
P0            |P1           |P2           ;
lwz r1,0(r7)  |li r1,1      |li r1,1      ;
              |stw r1,0(r8) |stw r1,0(r6) ;
stw r1,0(r6)  |lwsync       |;
lwz r3,0(r6)  |li r2,2      |;
xor r10,r3,r3 |stw r2,0(r7) |;
lwzx r2,r10,r8|             |;


Observed
    0:r1=2; 0:r2=0; 0:r3=1;