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

LISA auto/LB-GWW+R-Oc+R-Oc
(*
 * Result: Maybe
 * P0 GWW: Never->Maybe: Should rel-acq provide any global transitivity?
 * P0-P1 rf R-Oc: Note lack of C11 guarantee, control dependency
 * P1 Oc,R: Note lack of C11 guarantee
 * P1-P2 rf R-Oc: Note lack of C11 guarantee, control dependency
 * P2 Oc,GWW: Note lack of C11 guarantee, control dependency
 *)
{
 1:r4=1; 2:r4=1;
}
 P0              | P1                 | P2                 | P3            ;
 w[once] u0 3    | r[once] r1 x1      | r[once] r1 x2      | r[once] r1 v0 ;
 w[release] x1 1 | mov r4 (neq r1 r4) | mov r4 (neq r1 r4) | f[mb]         ;
                 | b[] r4 CTRL1       | b[] r4 CTRL2       | r[once] r2 u0 ;
                 | w[release] x2 1    | w[once] v0 1       |               ;
                 | CTRL1:             | CTRL2:             |               ;
Observed
    3:r2=0; 3:r1=1; 2:r1=1; 1:r1=1;