bug#58801: [PATCH] Autoload the `calc-eval-error' variable

[Eli Zaretskii]

> Cc: 58801@debbugs.gnu.org
> From: Matt Armstrong <matt@rfc20.org>
> Date: Tue, 15 Nov 2022 10:24:00 -0800
> 
> My first impression is that adding `defvar' to squash bytecomp warnings
> for symbols in other packages is the wrong default action

No, it's the standard solution for byte-compilation warnings.  There
are a few others, all of them better than an actual require.

> and that the best idea is for
> 
>   (require 'foo)
> 
> to provide all symbols 'foo-' that one might need when using the `foo'
> package in the normal way.

That actually loads the package foo, for no good reason.  We don't
necessarily want to use foo, we just want to compile a reference to
its variable or function.