bug#64185: proposal for new function: copy-line

[Eli Zaretskii]

> From: Juri Linkov <juri@linkov.net>
> Cc: zkanfer@gmail.com,  64185@debbugs.gnu.org,  me@eshelyaron.com
> Date: Thu, 22 Jun 2023 21:17:51 +0300
> 
> Unless someone has an idea for a shorter name that is still descriptive,
> here is the final patch for emacs-29:

LGTM, thanks.  But let's wait for a day or two to give others a chance
to comment.