Re: derived-mode-run-hooks

[Richard M. Stallman]

    However, the question is: should I expect for a 22.0.X .elc file to
    work on 21.4? I would've assumed "not", but for this comment on
    `define-derived-mode':

If it is easy to make this work (or work more), we can do it,
but I'd rather not do a lot of work for that sake.
I think that such compatibility is much less important than it once was.
It isn't hard to maintain two sets of .elc files if you have two
Emacs versions installed.