Test RW+RR-DSB+DSB+WREG

AArch64 RW+RR-DSB+DSB+WREG
TTHM=P0:HD
{
0:X1=x; 1:X1=x;
0:X3=y; 1:X3=y;
pte_x=(af:0);
}
P0          | P1             ;
LDR W0,[X1] | LDR W2,[X3]    ;
DSB SY      | DSB SY         ;
MOV W2,#1   | L0: LDR W0,[X1];
STR W2,[X3] |                ;
exists (1:X2=1 /\ fault(P1:L0,x,MMU:AccessFlag))