FpDebug: restructure dwarf classes, preparation for adding fpc specific subclasses

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@44598 4005530d-fff6-0310-9dd1-cebe43e6787f
FpDebug: restructure dwarf classes, preparation for adding fpc specific subclasses

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@44599 4005530d-fff6-0310-9dd1-cebe43e6787f