Test CoRW

AArch64 CoRW
"PosRW Wse Rfe"
Prefetch=
Com=Ws Rf
Orig=PosRW Wse Rfe
{
0:X1=x;
1:X1=x;
}
 P0          | P1          ;
 LDR W0,[X1] | MOV W0,#2   ;
 MOV W2,#1   | STR W0,[X1] ;
 STR W2,[X1] |             ;
exists
(x=2 /\ 0:X0=2)