debug_sortsupport GUC?

The text abbreviation code has a compile-time option to emit DEBUGn
elogs. I made no attempt to add these to the numeric abbreviation code
because I find such things completely unhelpful; when you need to
investigate such things other than in initial development, it's unlikely
that you will be in a position to recompile. Also, as I showed at some
length earlier, even recompiling with an apparently irrelevant change
can have enough of an effect on performance to make investigation more
complex.

So if these debugging elogs are to be kept at all, I propose that rather
than being compile-time options they should be controlled by a
debug_sortsupport GUC. Opinions?

--
Andrew (irc:RhodiumToad)