Test auto/LB-GWW+R-Dd+R-A

LISA auto/LB-GWW+R-Dd+R-A
(*
 * Result: Maybe
 * P0 GWW: Never->Maybe: Should rel-acq provide any global transitivity?
 *)
{
 0:r3=x2; x1=y1;
}
 P0               | P1              | P2               | P3            ;
 w[once] u0 3     | r[deref] r1 x1  | r[acquire] r1 x2 | r[once] r1 v0 ;
 w[release] x1 r3 | w[release] r1 1 | w[once] v0 1     | f[mb]         ;
                  |                 |                  | r[once] r2 u0 ;
Observed
    3:r2=0; 3:r1=1; 2:r1=1; 1:r1=x2;