Change the parameter for retrieving a certain precision from Class<T> to a Predicate. This is needed in the case that more CPAs use the same Precision Class but different instances. The only precision which is currently used in this way is the VariabletrackingPrecision. Instead of only creating an InstanceofPrededicte, according to the Class parameter before, we now check an additional field in the Precision to ensure that we found the correct one.
Every other Precision that should be used in more than one CPA should implement such a mechanism, otherwise it is not sure that the correct precision can be found.

git-svn-id: https://svn.sosy-lab.org/software/cpachecker/trunk@14232 4712c6d2-40bb-43ae-aa4b-fec3f1bdfe4c