A new release of Compat has been prepared (28.1.2.1). Quoting from the
NEWS file:
This is a minor release adding the following changes:
- Add `derived-mode-p' defined in Emacs 27
- Add `provided-mode-derived-p' defined in Emacs 27
- Add `read-multiple-choice' defined in Emacs 26
- Add `file-name-absolute-p' defined in Emacs 28
The only other notable change is that the manual has been rewritten to
include much more documentation that had been the case previously.