Test MP+dmb.sy+ctrl-pos

AArch64 MP+dmb.sy+ctrl-pos
"DMB.SYdWW Rfe DpCtrldR PosRR Fre"
Cycle=Rfe DpCtrldR PosRR Fre DMB.SYdWW
Relax=
Safe=Rfe Fre PosRR DMB.SYdWW DpCtrldR
Prefetch=0:x=F,0:y=W,1:y=F,1:x=T
Com=Rf Fr
Orig=DMB.SYdWW Rfe DpCtrldR PosRR Fre
{
0:X1=x; 0:X3=y;
1:X1=y; 1:X3=x;
}
 P0          | P1           ;
 MOV W0,#1   | LDR W0,[X1]  ;
 STR W0,[X1] | CBNZ W0,LC00 ;
 DMB SY      | LC00:        ;
 MOV W2,#1   | LDR W2,[X3]  ;
 STR W2,[X3] | LDR W4,[X3]  ;
Observed
    y=1; x=1; 1:X4=0; 1:X2=1; 1:X0=1;
and y=1; x=1; 1:X4=0; 1:X2=1; 1:X0=0;