Commit 2020-09-12T07:11:26Z!eliz@gnu.org 
(694acda5f24e356264c3f2a55a49812e02bcb49a) broke the build on AIX 7.2, 
as AIX uses libncurses for terminfo and its libncurses does not define 
UP, BC, or CP. Normally I'd just install the attached patch into the 
emacs-27 branch and then merge to master, but I thought I'd check on the 
mailing list since I don't offhand know how close we are to a 27.2 release.