Merge branch 'check-the-remaining-info_cnt-before-repeating-btf-fields'

Merge branch 'check-the-remaining-info_cnt-before-repeating-btf-fields'

Hou Tao says:

====================
Check the remaining info_cnt before repeating btf fields

From: Hou Tao <houtao1@huawei.com>

Hi,

The patch set adds the missed check again info_cnt when flattening the
array of nested struct. The problem was spotted when developing dynptr
key support for hash map. Patch #1 adds the missed check and patch #2
adds three success test cases and one failure test case for the problem.

Comments are always welcome.

Change Log:
v2:
 * patch #1: check info_cnt in btf_repeat_fields()
 * patch #2: use a hard-coded number instead of BTF_FIELDS_MAX, because
             BTF_FIELDS_MAX is not always available in vmlinux.h (e.g.,
	     for llvm 17/18)

v1: https://lore.kernel.org/bpf/20240911110557.2759801-1-houtao@huaweicloud.com/T/#t
====================

Link: https://lore.kernel.org/r/20241008071114.3718177-1-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>