all those pesky math functions

[Gabriel Dos Reis]

Phil Edwards <pedwards@disaster.jaj.com> writes:

| Checking for those functions consumes much of the time spent in
| 'configure'.  Are those checks the kind that can be safely cached?

At first sight, I'd say caching them should be OK, but hey I've been
so repeatedly surprised by those beasts that I can't say with
confidence that caching is safe.  Let's go that way.  If it breaks
then we'll something :-). 

-- Gaby