Test Weak-RCU-Readers

LISA Weak-RCU-Readers (*Paul says allowed*)
{
x = 0; y = 0;
}
 P0                 | P1                 ;
 f[rcu_read_lock]   | f[rcu_read_lock]   ;
 r[once] r1 x       | r[once] r2 y       ;
 f[rcu_read_unlock] | f[rcu_read_unlock] ;
 f[rcu_read_lock]   | f[rcu_read_lock]   ;
 w[once] y 1        | w[once] x 1        ;
 f[rcu_read_unlock] | f[rcu_read_unlock] ;
Observed
    1:r2=1; 0:r1=1;