Test coRWExpNExp

AArch64 coRWExpNExp
TTHM=HD
{
0:X1=pte_x;
pte_x=(db:0,dbm:1);
0:X4=x;
}
P0         ;
LDR X2,[X1];
MOV W3,#1  ;
STR W3,[X4];
exists (0:X2=(oa:PA(x), dbm:1))