Test MP+dmb.sy+ctrl-pos-[fr-rf]-pos

AArch64 MP+dmb.sy+ctrl-pos-[fr-rf]-pos
"DMB.SYdWW Rfe DpCtrldR PosRR FrLeave RfBack PosRR Fre"
Cycle=Rfe DpCtrldR PosRR FrLeave RfBack PosRR Fre DMB.SYdWW
Relax=
Safe=Rfe Fre PosRR DMB.SYdWW DpCtrldR [FrLeave,RfBack]
Prefetch=0:x=F,0:y=W,1:y=F,1:x=T
Com=Rf Fr Rf
Orig=DMB.SYdWW Rfe DpCtrldR PosRR FrLeave RfBack PosRR Fre
{
0:X1=x; 0:X3=y;
1:X1=y; 1:X3=x;
2:X1=x;
}
 P0          | P1           | P2          ;
 MOV W0,#2   | LDR W0,[X1]  | MOV W0,#1   ;
 STR W0,[X1] | CBNZ W0,LC00 | STR W0,[X1] ;
 DMB SY      | LC00:        |             ;
 MOV W2,#1   | LDR W2,[X3]  |             ;
 STR W2,[X3] | LDR W4,[X3]  |             ;
             | LDR W5,[X3]  |             ;
             | LDR W6,[X3]  |             ;
Observed
    y=1; x=2; 1:X6=2; 1:X5=1; 1:X4=1; 1:X2=0; 1:X0=1;