Get BTF objects by name

[qmonnet]

From man bpftool-btf:

 BTF_SRC := { id BTF_ID | prog PROG | map MAP [{key | value | kv | all}] | file FILE }

We could support passing BTF objects by name as well, e.g. vmlinux or any module name.

[qmonnet]

https://lore.kernel.org/r/[email protected]