configure.ac: add support for GNU/kFreeBSD, accepted by upstream for gc 6.8.

2006-06-07  Petr Salinger  <Petr.Salinger@seznam.cz>

	* configure.ac: add support for GNU/kFreeBSD, accepted by upstream
	for gc 6.8.
	* dyn_load.c: Likewise.
	* include/gc.h: Likewise.
	* private/gcconfig.h: Likewise.
	* configure: Regenerate.
	* include/gc_config.h.in: Regenerate.

From-SVN: r117033