Unlike other FreeWare compilers, GNU Pascal is *not* intended to be 100% Borland compatible. GNU Pascal is part of the GNU project, so portability is one of its primary goals. For this reason, non-portable features of Borland Pascal will probably not be included into GNU Pascal. Some other differences are so minimal that we have more important things to do than to implement them.
However if you want to contribute to GNU Pascal by eliminating holes in GPC's Borland compatibility, be welcome in the GNU Pascal development team! See See section How you can contribute to GNU Pascal for details.