Should we automatically run duplicate_oids?

When rebasing a patch that I'm working on, I occasionally forget to
update the oid of any pg_proc.h entries I may have created. Of course
this isn't a real problem; when I go to initdb, I immediately
recognize what has happened. All the same, it seems like there is a
case to be made for having this run automatically at build time, and
having the build fail on the basis of there being a duplicate - this
is something that fails reliably, but only when someone has added
another pg_proc.h entry, and only when that other person happened to
choose an oid in a range of free-in-git-tip oids that I myself
fancied.

Sure, I ought to remember to check this anyway, but it seems
preferable to make this process more mechanical. I can point to commit
55c1687a as a kind of precedent, where the process of running
check_keywords.pl was made to run automatically any time gram.c is
rebuilt. Granted, that's a more subtle problem than the one I'm
proposing to solve, but I still see this as a modest improvement.

--
Peter Geoghegan