#23 extremely minor configure.in patch

[Faried Nawaz]

A test was missing a sys/stat.h include. I very much
doubt that this
helps or hurts anyone.

However, there is a bigger problem. On some systems,
only the
superuser can call mknod(2). On some of these systems,
mknod(2)
doesn't create fifos! You have to use mkfifo(2),
which, apparently,
can be used by root and mere mortals. Lots of tests
use mknod(2),
so it's worth fixing. I only have access to newer
operating systems,
so I can't login somewhere and check if (say) SunOs 4.x
supports
mkfifo(2) or not.

[Faried Nawaz]

sys/stat.h patch