bug#63415: 30.0.50; More Build Warnings

[Eli Zaretskii]

> From: Jacob Faibussowitsch <jacob.fai@gmail.com>
> Date: Thu, 11 May 2023 09:39:59 -0400
> Cc: Andrea Corallo <akrl@sdf.org>,
>  63415@debbugs.gnu.org
> 
> > Avoiding it is too much
> > trouble (will make the code harder to read), and this configuration is
> > rare enough to not justify that.  So I've left that alone.
> 
> FWIW the following silences the warning. But up to you

Thanks, I'd rather not do that, especially since some recent versions
of GCC are beginning to ignore such "usage", AFAIR.

We could perhaps use some variable attributes, but that'd make the
code less portable to various compilers, and will again require cpp
conditionals, which make the code uglier and harder to read.