bug#81537: 32.0.50; Fixing icomplete-in-buffer requiring users to advice-add

> Either I am misunderstanding you or I completely disagree, as an
> Icomplete user for a long time.  It would be a huge distraction if
> Icomplete kept showing up during ordinary typing, just because
> completion was possible.  And, I specifically want Icomplete to replace
> *Completions*, because they serve basically the same purpose.
>
> What you are describing sounds more like completion-preview-mode.

Yes, this is more like completion-preview-mode.

So what remains to do here is just to remove mentions of
package-specific prefixes "icomplete-" from the general file
minibuffer.el by adding a new hook like e.g. 'disable-completion-list'.