port-amd64/58096: booting with x86 multiboot doesn't pass ctf data

[campbell+netbsd%mumble.net@localhost]

>Number:         58096
>Category:       port-amd64
>Synopsis:       booting with x86 multiboot doesn't pass ctf data
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-amd64-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Apr 01 20:35:00 +0000 2024
>Originator:     Taylor R Campbell
>Release:        current, 10, 9, 8, ...
>Organization:
The NetCTF Bootdation
>Environment:
>Description:
multiboot (1 and 2) uses ksyms_addsyms_explicit which has no provision for passing ctf data through:

https://nxr.netbsd.org/xref/src/sys/arch/i386/i386/multiboot.c?r=1.26#710
https://nxr.netbsd.org/xref/src/sys/arch/x86/x86/multiboot2.c?r=1.8#1061

This means that the kernel ELF object has no ctf data, which breaks a lot of dtrace.
>How-To-Repeat:
`dtrace -l -P fbt' produces no output from netbsd (just from solaris.kmod and other modules you've loaded)
>Fix:
Yes, please!