lib/58843: libevent leaks private and zstd symbols

[campbell+netbsd%mumble.net@localhost]

>Number:         58843
>Category:       lib
>Synopsis:       libevent leaks private and zstd symbols
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    lib-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Nov 22 00:10:00 +0000 2024
>Originator:     Taylor R Campbell
>Release:        current, 10, 9, ...
>Organization:
The NetBSD Eventually.so
>Environment:
>Description:
Upstream builds libevent with -fvisibility=hidden and exported symbols explicitly marked, but we don't, so various private symbols are exported that shouldn't be, like `kqops'.
>How-To-Repeat:
nm, code inspection
>Fix:
use -fvisibility=hidden, update expected symbols list, bump major