Test RSV+FAIL

PPC RSV+FAIL
"store conditional by P1 must fail"
{
0:r2=x;
1:r2=x; 1:r4=y;
}
 P0           | P1              ;
 li r1,1      | lwarx r1,r0,r2  ;
 stw r1,0(r2) | lwarx r3,r0,r4  ;
              | li r5,2         ;
              | stwcx. r5,r0,r2 ;
~exists (x=2)