MayLock Analysis & Sanity Checks of Mutex Usage & Analysis of Mutex Types

[michael-schwarz]

Some in-progress work on a May Lock Analysis that allows us to detect potential may double locking. Also contains some first attempt of tracking whether a mutex is potentially recursive or not, in order to emit appropriate warnings.

Relates (partially) to:

1. Mutex/thread sanity analysis #176
2. Proper support for mutex type PTHREAD_MUTEX_ERRORCHECK checking return types #658
3. Switch to HoareSet for MayLocks #718
4. Maintain more precise lockset for recursive mutexes #800

[sim642]

The last big question is how expensive these things are. Ideally we could just have these activated by default.

[michael-schwarz]

I will merge them for now (without changing the defaults), and do an sv-comp run after!