[patch, configures] Unify AC_SYS_LARGEFILE exception across dirs

[Joel Brobecker]

> config/
> 2009-11-06  Jan Kratochvil  <jan.kratochvil@redhat.com>
> 	    Joel Brobecker  <brobecker@adacore.com>
> 	    Paolo Bonzini  <bonzini@gnu.org>
> 
> 	* largefile.m4: New file.

Now checked in both GCC and GDB, with the wording correction suggested
by Paolo. Woohoo :).

-- 
Joel