Privatizations unsound when threadflag analysis deactivated

[sim642]

In #859 one of the autotune unsoundness cases was caused by autotune deactivating the threadflag analysis. A minimized TODO test is added here: 505b669.

The problem is, when threadflag is deactivated, EnterMultithreaded event is never emitted and thus privatizations don't correctly publish initial values, in that particular case to MUTEX_INITS. I'm not sure which privatizations (both base and apron) are affected, possibly all non-trivial ones.

[michael-schwarz]

I was unable to reproduce this issue with the newer versions of Goblint. Closing for now.