Test RW-rwa+RW-ra+RW-rra+CK

LISA RW-rwa+RW-ra+RW-rra+CK
(*
 * Result: Sometimes, due to release-acquire being only locally transitive.
 * I believe that this is allowed by PowerPC.
 *)
{
}
 P0               | P1               | P2               | P3            ;
 w[once] y 1      | r[acquire] r1 x1 | r[acquire] r1 x2 | w[once] z 1   ;
 w[release] x1 1  | w[release] x2 1  | r[once] r2 z     | f[mb]         ;
                  |                  |                  | r[once] r1 y  ;
Observed
    3:r1=0; 2:r2=0; 2:r1=1; 1:r1=1;