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

AArch64 MP+dmb.sy+[fr-rf]-ctrl-pos-ctrl
"DMB.SYdWW Rfe FrLeave RfBack DpCtrldR PosRR DpCtrldR Fre"
Cycle=Rfe FrLeave RfBack DpCtrldR PosRR DpCtrldR 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 FrLeave RfBack DpCtrldR PosRR DpCtrldR Fre
{
0:X1=x; 0:X3=y;
1:X1=y; 1:X4=z; 1:X7=x;
2:X1=y;
}
 P0          | P1           | P2          ;
 MOV W0,#1   | LDR W0,[X1]  | MOV W0,#2   ;
 STR W0,[X1] | LDR W2,[X1]  | STR W0,[X1] ;
 DMB SY      | CBNZ W2,LC00 |             ;
 MOV W2,#1   | LC00:        |             ;
 STR W2,[X3] | LDR W3,[X4]  |             ;
             | LDR W5,[X4]  |             ;
             | CBNZ W5,LC01 |             ;
             | LC01:        |             ;
             | LDR W6,[X7]  |             ;
Observed
    y=1; x=1; 1:X6=1; 1:X2=0; 1:X0=2;
and y=1; x=1; 1:X6=0; 1:X2=0; 1:X0=2;
and y=1; x=1; 1:X6=1; 1:X2=0; 1:X0=1;