kern/57373: sys_kfilters should be a link set

[campbell+netbsd%mumble.net@localhost]

>Number:         57373
>Category:       kern
>Synopsis:       sys_kfilters should be a link set
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Apr 22 09:55:00 +0000 2023
>Originator:     Taylor R Campbell
>Release:        current
>Organization:
the knetbsd foundation
>Environment:
inextricably linked with fossil fuel consumption
>Description:
Instead of having a bunch of externs hard-coded into kern_event.c for a fixed table of system-defined kfilters, this should be defined with a link set.
>How-To-Repeat:
$ nm --undefined-only librump.so | grep rumpns
...
                 U rumpns_fs_filtops
...

>Fix:
Yes, please!