Test S+po+poxx+SYS2

AArch64 S+po+poxx+SYS2
"PodWW RfePX PodRWXX WseXP"
Cycle=PodWW RfePX PodRWXX WseXP
Relax=RfePX WseXP
Safe=PodWW PodRW
Prefetch=0:x=F,0:y=W,1:y=F,1:x=W
Com=Rf Ws
Orig=PodWW RfePX PodRWXX WseXP
{
0:X1=x; 0:X3=y;
1:X0=y; 1:X3=x;
}
 P0          | P1              ;
 MOV W0,#2   | LDXR W1,[X0]    ;
 STR W0,[X1] | STXR W2,W1,[X0] ;
 MOV W2,#1   | MOV W4,#1       ;
 STR W2,[X3] | LDXR W5,[X3]    ;
             | STXR W6,W4,[X3] ;
exists
(x=2 /\ y=1 /\ 1:X6=0 /\ 1:X2=0 /\ 1:X1=1 /\ 1:X5=0)