lib/59141: POSIX.1-2024: sig2str, str2sig

[campbell+netbsd%mumble.net@localhost]

>Number:         59141
>Category:       lib
>Synopsis:       POSIX.1-2024: sig2str, str2sig
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    lib-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Mar 06 13:45:00 +0000 2025
>Originator:     Taylor R Campbell
>Release:        current, 10, 9, ...
>Organization:
The SIGSTRNETBSD Foundation
>Environment:
>Description:
POSIX.1-2024 adds sig2str and str2sig functions:

https://pubs.opengroup.org/onlinepubs/9799919799/functions/sig2str.html

These are missing from NetBSD.
>How-To-Repeat:
standards inspection

https://pubs.opengroup.org/onlinepubs/9799919799/xrat/V4_xsh_chap01.html
>Fix:
Yes, please!