bug#44645: dired-do-rename: check before asking doomed command

["積丹尼 Dan Jacobson" <jidanni@jidanni.org>]

Create a directory, then move it to /tmp.
Then do that all a second time.

R runs the command dired-do-rename.
It should do some check before asking about command doomed to fail:

Overwrite ‘/tmp/google-chrome-unstable’? [Type yn!q or C-h] y
Move: ‘/home/jidanni/.config/google-chrome-unstable’ to ‘/tmp/google-chrome-unstable’ failed:
(file-already-exists File exists /tmp/google-chrome-unstable)

Also that last line,
(file-already-exists File exists /tmp/google-chrome-unstable)
 ^^^^         ^^^^^^ ^^^^ ^^^^^^
seems to repeat itself. (Looks bad.)
(Also aren't these directories, not just files?)

OK, trying again with the shell
$ mv -i .config/google-chrome-unstable/ /tmp/
mv: overwrite '/tmp/google-chrome-unstable'? y
mv: inter-device move failed: '.config/google-chrome-unstable/' to
'/tmp/google-chrome-unstable'; unable to remove target: Directory not empty

OK, I guess checking too much ahead every time isn't worth the overhead.
If so, close this bug.

emacs-version "27.1"