Test ppo7

PPC ppo7 (PPCPPOSeven)
"bc;isync idiom for building ppo, without isync"
{
0:r6=x; 0:r7=y;
1:r6=x; 1:r7=y;
}
P0            |P1           ;
lwz r1,0(r6)  |li r1,1      ;
cmpw r1,r1    |stw r1,0(r7) ;
bne L0        |sync         ;
L0:           |li r2,2      ;
lwz r2,0(r7)  |stw r2,0(r6) ;


locations [0:r1; 0:r2;]
exists (0:r1=2 /\ 0:r2=0)