success even though no CTF section was present in the kernel or module.
This fixes the panic that several people saw when trying out the FBT
provider without updating /boot or missing a CTF section in /netbsd.
at boot.
Add a ksyms_mod_foreach() function to iterate a callback function over the
set of elf symbols for a specific module (netbsd included).
Add kern_ctf.c and mod_ctf_get() to allow the retrieval and decompression
of CTF sections for a specific module.