bug#43725: 28.0.50; Include feature/native-comp into master

[Andrea Corallo]

Eli Zaretskii <eliz@gnu.org> writes:

>> Date: Fri, 02 Oct 2020 19:39:29 +0000
>> From: Andrea Corallo via "Bug reports for GNU Emacs,
>>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
>> 
>> redefining primitives does not take effect in optimized code
>
> Why doesn't it?  Can it be made to take effect, like it does in
> interpreted code?

Mmmh, I think technically we could, similarly to what we do for the
advice, synthesize compile and install a trampoline.  This would read
the symbol-function and calls what's in inside.

This trampoline installation would be triggered inside Ffset.

So yeah I think we could, if that's the preferred way I can try this
way.

  Andrea