Test MP+isync+lwsync

PPC MP+isync+lwsync
"ISyncdWW Rfe LwSyncdRR Fre"
Cycle=Rfe LwSyncdRR Fre ISyncdWW
{
0:r2=x; 0:r4=y;
1:r2=y; 1:r4=x;
}
 P0           | P1           ;
 li r1,1      | lwz r1,0(r2) ;
 stw r1,0(r2) | lwsync       ;
 isync        | lwz r3,0(r4) ;
 li r3,1      |              ;
 stw r3,0(r4) |              ;
exists
(1:r1=1 /\ 1:r3=0)