Test auto/LB-LRR+R-A+O-Dd

LISA auto/LB-LRR+R-A+O-Dd
(*
 * Result: Maybe
 * P1-P2 rf O-Dd: Never->Maybe: Note lack of C11 guarantee, no synchronizes-with
 *)
{
 1:r3=u0; x2=y2;
}
 P0              | P1               | P2             | P3           ;
 r[once] r1 u0   | r[acquire] r1 x1 | r[deref] r1 x2 | w[once] u0 1 ;
 w[release] x1 1 | w[once] x2 r3    | r[once] r2 r1  |              ;
Observed
    2:r2=0; 2:r1=u0; 1:r1=1; 0:r1=1;