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

LISA auto/LB-GWW+R-A+R-A+R-Oc
(*
 * Result: Maybe
 * P0 GWW: Never->Maybe: Should rel-acq provide any global transitivity?
 * P2-P3 rf R-Oc: Note lack of C11 guarantee, control dependency
 * P3 Oc,GWW: Note lack of C11 guarantee, control dependency
 *)
{
 3:r4=1;
}
 P0              | P1               | P2               | P3                 | P4            ;
 w[once] u0 3    | r[acquire] r1 x1 | r[acquire] r1 x2 | r[once] r1 x3      | r[once] r1 v0 ;
 w[release] x1 1 | w[release] x2 1  | w[release] x3 1  | mov r4 (neq r1 r4) | f[mb]         ;
                 |                  |                  | b[] r4 CTRL3       | r[once] r2 u0 ;
                 |                  |                  | w[once] v0 1       |               ;
                 |                  |                  | CTRL3:             |               ;
Observed
    4:r2=0; 4:r1=1; 3:r1=1; 2:r1=1; 1:r1=1;