CPT: SMP race in detecting state of ptraced processes
When suspending VE, we test state of processes while they are
still running. It is not a bug: we have to verify for invalid state
before checkpointing, real state is saved after processes are scheduled
The impact is that we can see process in a bad state, f.e. stopped
without any reasons. It is also not a bug, but this rersults in random
failures of checkpointing. The only way to fix this is to order updates
of state variables. The order is correct almost everywhere.