bug#48264: [PATCH v3 15/15] Add and use BVAR_FIELD macros

[Eli Zaretskii]

> From: Spencer Baugh <sbaugh@catern.com>
> Cc: 48264@debbugs.gnu.org
> Date: Sat, 08 May 2021 15:03:46 -0400
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> >> From: Spencer Baugh <sbaugh@catern.com>
> >> Cc: 48264@debbugs.gnu.org
> >> Date: Sat, 08 May 2021 09:35:31 -0400
> >> If you think such a conditionally-compiled runtime check would be
> >> acceptable for applying these changes, I can go ahead and write that.
> >
> > Yes, I think so.  But if Lars or Stefan think differently, I might
> > reconsider.
> 
> In the process of implementing the runtime check, I, of course, came up
> with a better compile-time check. How about this?

LGTM, thanks.  But could you please run your benchmarks again, with
this implementation, to make sure we still get only a 1 - 2% slowdown
at worst?  I wouldn't expect the addition to matter in an optimized
build, but just to be sure...