LazDebuggerFp (pure): do not crash range check

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@44637 4005530d-fff6-0310-9dd1-cebe43e6787f
LazDebuggerFp (pure): Fixed crash of the IDE on exit.

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@44638 4005530d-fff6-0310-9dd1-cebe43e6787f