FpDebug (pure): Do not try to set register-values twice

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@45765 4005530d-fff6-0310-9dd1-cebe43e6787f
FpDebug (pure): Set uninitialized function result

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@45766 4005530d-fff6-0310-9dd1-cebe43e6787f