These sweeps are supposed to have some tangible benefit. If we have
removed functionality as a result then we have to look at the benefit
of the sweep.

Guess what?  For this one, there is no benefit. It's a move-to-C99 cleanup
that did not actually gain functionality, just _slightly_ less #define complexity,
and it backfired.  It removed functionality.

I think stuff that worked via ./configure (no pkgsrc) before should still
work after one of these "harmless" sweeps. 

Since we gain absolutely nothing by this sweep, except a purely intangible
"I like the code better this way" then it seems like a backout is called for...

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