Re: AIX support

I wrote:
> cfarm119 soon reminded me that I'd forgotten about the lgamma(NaN)
> problem discussed in [1].  I'm inclined to go ahead and push the
> patch shown there.

[ time passes ... ]  OK, cfarm119 is also happy, given the addition
of that patch.

So we should be good to go on re-enabling douc to run on master.
(BTW, it looks like it hasn't run on the back branches either
for a couple of weeks?)

            regards, tom lane