Test gros-cycle

PPC gros-cycle
"LwSyncdRW Wse Rfe LwSyncdRR Fre SyncdWW Rfe"

(*
   This example is interesting because
   its cycle is non-global (Rfe LwSyncdRR)
   but nevertheless includes a blocked
   critical cycle: LwSyncdRW Rfe LwSyncdRR Fre SyncdWW Rfe
*)
{
0:r2=z; 0:r4=x;
1:r2=x;
2:r2=x; 2:r4=y;
3:r2=y; 3:r4=z;
}
 P0           | P1           | P2           | P3           ;
 lwz r1,0(r2) | li r1,2      | lwz r1,0(r2) | li r1,1      ;
 lwsync       | stw r1,0(r2) | lwsync       | stw r1,0(r2) ;
 li r3,1      |              | lwz r3,0(r4) | sync         ;
 stw r3,0(r4) |              |              | li r3,1      ;
              |              |              | stw r3,0(r4) ;
exists
(x=2 /\ 0:r1=1 /\ 2:r1=2 /\ 2:r3=0)