bug#52356: 27.2; Isearch prompt changes unexpectedly with char folding enabled

[Juri Linkov]

Hello Andrea,

> your patch works for me. If you’re going to submit it for merging
> you might consider replacing the old line with
>
>     (or (eq this-command 'isearch-del-char)
>
> just to avoid using ‘memq’ for comparing against a single item.

I'm still not sure about this change.  Do you think this problem
exists only when isearch-lazy-count is customized to t?
Do you see the same problem with the "pending" message
while using the default value of isearch-lazy-count nil?