Test rcu-relacq2

LISA rcu-relacq2
""
{
}
 P0                 | P1          | P2             ;
 r[once] r0 x       | w[once] y 2 | w[once] u 1    ;
 w[once] y r0       | f[sync]     | w[release] x 1 ;
 f[rcu_read_lock]   | w[once] v 1 |                ;
 r[once] r1 u       |             |                ;
 r[once] r2 v       |             |                ;
 f[rcu_read_unlock] |             |                ;
Observed
    y=2; 0:r2=0; 0:r1=0; 0:r0=1;