From 35fe9c79f76ed2955b7d27ea22b4b419aa4bf544 Mon Sep 17 00:00:00 2001
From: Trevor Gross <tmgross@umich.edu>
Date: Fri, 22 Nov 2024 20:46:20 -0500
Subject: [PATCH] Add a test that the `const extern fn` macro works

By default, any functions defined in this macro (such as `CMSG_SPACE`)
should be `const`.

(backport <https://github.com/rust-lang/libc/pull/4134>)
(cherry picked from commit 0304ed535e94eb81f1ea5931c12f57ad95bb69ee)

No change in the cherry pick since the function came from libc-0.2
originally.