lib/58845: libposix exports __posix_cerror on some architectures but not others

[campbell+netbsd%mumble.net@localhost]

>Number:         58845
>Category:       lib
>Synopsis:       libposix exports __posix_cerror on some architectures but not others
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    lib-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Nov 22 14:40:00 +0000 2024
>Originator:     Taylor R Campbell
>Release:        current, 10, 9, ...
>Organization:
The NetBSD __posix_Founderror
>Environment:
>Description:
amd64 libposix.so defines __posix_cerror, but aarch64 libposix.so does not.

If this is intentional, we need machine-dependent expected symbol lists (for PR PR lib/58838: shared libraries in base should all have expsym lists, https://gnats.NetBSD.org/58838).

If this is unintentional, we need to diagnose why and maybe fix it.
>How-To-Repeat:
write a .expsym file for libposix.so and watch a slew of builds fail
>Fix:
Yes, please!