[libstdc++ PATCH] Fix PR bootstrap/11272

[Benjamin Kosnik]

>2003-06-21  Eric Botcazou  <ebotcazou@libertysurf.fr>
>
>	PR bootstrap/11272
>	Backport from mainline:
>
>	2003-03-09  Paolo Carlini  <pcarlini@unitus.it>
>
>	* config/io/basic_file_stdio.cc: include <unistd.h>.

Fine.