bug#5863: defadvice in byte compiled file does not work

[Stefan Monnier]

> BTW, it seems like advising primitives will work once we get native-comp
> merged:
>
>   The result of this procedure is that each newly activated function will
>   use the trampoline in place of the original primitive and the
>   trampoline will execute the call going through funcall making the
>   advice effective!
>
>   This works so well that in-fact now is even possible to advice
>   effectively what wasn't effective in byte-code (ex the + function). But
>   hey, don't try this a home!
>
>   https://akrl.sdf.org/gccemacs.html#org3b7398e

AFAIK this still won't cover all cases: we'd additionally have to
arrange for C calls to F<fun> to go through the trampoline.  Maybe we
can do that cheaply, I don't know.

In any case, I think the story is still sufficiently complex that we're
better off saying that "it may work or not depending on your luck".


        Stefan