Test auto/LB-LRR+R-Dd+R-Oc

LISA auto/LB-LRR+R-Dd+R-Oc
(*
 * Result: Sometimes
 * P1-P2 rf R-Oc: Never->Maybe: Note lack of C11 guarantee, control dependency
 * P2 Oc,LRR: Maybe->Sometimes: Control dependencies do not order trailing reads
 *)
{
 0:r3=x2; x1=y1; 2:r4=1;
}
 P0               | P1              | P2                 | P3           ;
 r[once] r1 u0    | r[deref] r1 x1  | r[once] r1 x2      | w[once] u0 1 ;
 w[release] x1 r3 | w[release] r1 1 | mov r4 (neq r1 r4) |              ;
                  |                 | b[] r4 CTRL2       |              ;
                  |                 | r[once] r2 u0      |              ;
                  |                 | CTRL2:             |              ;
Observed
    2:r2=0; 2:r1=1; 1:r1=x2; 0:r1=1;