[21.5] Check for ar, fix 2.13-ism

[Martin Buchholz]

>>>>> "S" == Stephen J Turnbull <stephen at xemacs.org> writes:

S> Sun hides utilities such as ar; this patch makes configure barf,
S> rather than letting you get all the way to installation.

My Solaris has copies of "ar" in both /usr/ccs/bin and /usr/xpg4/bin

-r-xr-xr-x   1 root     bin        31176 Aug 10  2005 /usr/ccs/bin/ar*
-r-xr-xr-x   1 root     bin        31120 Aug 10  2005 /usr/xpg4/bin/ar*

It might be worth using one of those explicitly on a Solaris system,
regardless of the value of PATH (but that's a lot of work).

----

I also think that "long" is a better choice for ssize_t than "int",
when ssize_t is unavailable.

Even better yet, but much more work, would be to check which of "int",
"long", "long long" is of the same size as size_t, and use that.

Martin