[Mesa-dev] [PATCH] autoconf: Enable missing-prototypes errors when available.

[Matt Turner]

> Looks OK to me.  I've wondered whether we want to import the macro for
> checking these things from xorg-util-macros, since we'll probably want to do
> this for a few other ones too.

I think that might be good eventually, but there's so much stuff in
configure.ac to be cleaned, I think it should probably wait until
after the transition to automake is finished.