Test MP+rel+cascqWZR

AArch64 MP+rel+cascqWZR
(* Allowed, CASA ..,WZR,.. by P1 does not have Acquire semantics *)
{
  x=0; y=1; z=0;
  0:X0=x; 1:X0=x;
  0:X1=y; 1:X1=y;
  1:X2=z;
}

  P0           |  P1               ;
  MOV W9,#1    |  MOV W9,#2        ;
  STR W9,[X0]  |  CASA WZR,W9,[X1] ;
  MOV W8,#0    |  LDR W8,[X0]      ;
  STLR W8,[X1] |                   ;


Observed
    y=2; 1:X8=0;