Enhance non-relational Mutex Meet with MHP

[michael-schwarz]

There is no reason we cannot also make use of MHP in the non-relational Mutex-Meet privatization. This should be added such that we can, e.g. profit from MHP information to gain more precise information about structs.

Very little new code should need to be added to achieve this, as many things are the same between relational and non-relational MM.