PG: robustness for huge coordinates in spatial filter

git-svn-id: https://svn.osgeo.org/gdal/trunk/gdal@26752 f0d54148-0727-0410-94bb-9a71ac55c965
MySQL: robustness for huge coordinates in spatial filter

git-svn-id: https://svn.osgeo.org/gdal/trunk/gdal@26753 f0d54148-0727-0410-94bb-9a71ac55c965