Fix newly introduced bug in Value Analysis in r14437:
Comparison of numeric values cannot be handled by the NumericValue.equals method,
so only use comparison by a value's equals method if no other case holds.



git-svn-id: https://svn.sosy-lab.org/software/cpachecker/trunk@14440 4712c6d2-40bb-43ae-aa4b-fec3f1bdfe4c