bug#43652: [PATCH] cperl-mode: Add helpers to run on Emacs 26.1
I plan to suggest that cperl-mode.el gets a "dual life" in both Emacs
and on ELPA on emacs-devel.
As a preparation, I added two helpers for the newer functions
'time-convert' and 'format-patch', following a suggestion by Stefan
Monnier. He actually wrote cperl--format-patch in a message to
emacs-devel and therefore is listed as co-author in the commit message.