Test S+poxx+popx+SYS2

AArch64 S+poxx+popx+SYS2
"PodWWXX RfeXP PodRWPX WseXX"
Cycle=PodRWPX WseXX PodWWXX RfeXP
Relax=RfeXP WseXX
Safe=PodWW PodRW
Prefetch=0:x=F,0:y=W,1:y=F,1:x=W
Com=Rf Ws
Orig=PodWWXX RfeXP PodRWPX WseXX
{
0:X0=x; 0:X4=y;
1:X1=y; 1:X2=x;
}
 P0              | P1              ;
 MOV W1,#2       | LDR W0,[X1]     ;
 LDXR W2,[X0]    | MOV W3,#1       ;
 STXR W3,W1,[X0] | LDXR W4,[X2]    ;
 MOV W5,#1       | STXR W5,W3,[X2] ;
 LDXR W6,[X4]    |                 ;
 STXR W7,W5,[X4] |                 ;
exists
(x=2 /\ y=1 /\ 0:X7=0 /\ 0:X3=0 /\ 0:X2=1 /\ 0:X6=0 /\ 1:X5=0 /\ 1:X0=1 /\ 1:X4=0)