bug#49069: 28.0.50; [PATCH] Use display-buffer for re-builder

[Juri Linkov <juri@linkov.net>]

>> Sorry, preventing the users from customizing windows is the wrong thing.
>
> I don't know really, let me explain my rational : some users have a very
> constrained display-buffer-alist and match ".*". You can see such
> rational explained at the end of this page :
>
> https://github.com/nex3/perspective-el

Thanks for the reference.  Now I understand the reason for such absurdity
in org-mode:

  (defmacro org-no-popups (&rest body)
    "Suppress popup windows and evaluate BODY."
    `(let (pop-up-frames display-buffer-alist)
       ,@body))

So different packages are fighting with each other:
one package recommends using display-buffer-alist to display
all buffers only in the same window, another package
throws away user customization on such grounds
that users might follow such poor recommendations.

The correct way to display all buffers in the same window
is documented in (info "(emacs) Window Choice") where
display-buffer-base-action should be customized like this:

  (customize-set-variable
   'display-buffer-base-action
   '((display-buffer-reuse-window display-buffer-same-window)))

And the problem is solved.  So please avoid ignoring user customization
with display-buffer-overriding-action because users with such
display-buffer-base-action will be able to customize "*RE-Builder*" with
display-buffer-alist.