Test CoWR

Run CoWR in model, using ppcmem

PPC CoWR (CoFour)
"PPC uniproc, basic reject (fr)"
{
0:r5=x; 1:r5=x;
}
P0           | P1          ;
li r1,1      |li r1,2      ;
stw r1,0(r5) |stw r1,0(r5) ;
lwz r2,0(r5) |             ;
~exists (x=1 /\ 0:r2=2)