Merge branch 'libbpf-introduce-line_info-and-func_info-getters'

Mykyta Yatsenko says:

====================
libbpf: introduce line_info and func_info getters

From: Mykyta Yatsenko <yatsenko@meta.com>

This patchset introduces new libbpf API getters that enable the retrieval
of .BTF.ext line and func info.
This change enables users to load bpf_program directly using bpf_prog_load,
bypassing the higher-level bpf_object__load API. Providing line and
function info is essential for BPF program verification in some cases.

v3 -> v5
 * Fix tests on s390x, nits.

v2 -> v3
 * Return ENOTSUPP if func or line info struct size differs from the one in
 uapi linux headers.
 * Add selftests.

v1 -> v2
 Move bpf_line_info_min and bpf_func_info_min from libbpf_internal.h to
 btf.h. Did not remove _min suffix, because there already are bpf_line_info
 and bpf_func_info structs in uapi/../bpf.h.
====================

Link: https://patch.msgid.link/20250408234417.452565-1-mykyta.yatsenko5@gmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>