esup byte compile warnings

[Serghei Iakovlev]

Hello,

There are `esup' [1] byte compile warnings I would like avoid to.
Some of them seems trivial to me.  However, I don't quite understand
slots related warnings.  In general I would like to realize on how
to deal with such kind of warnings and I need help.  In fact, I
often come across something similar and I'll appreciate it if you
help me deal with such warnings.

N.B. This happens in Emacs 28.0.50 as well as in 27.0.60

[1]: https://github.com/jschaf/esup/issues/68

-- 
Serghei