Merge branch 'bpf-maximum-combined-stack-depth'

Paul Chaignon says:

====================
bpf: Maximum combined stack depth

This patchset dumps the maximum combined stack depth in verifier logs
and parses it in veristat.

Changes in v3:
  - Increment spec_cnt field in veristat for new MAX_STACK id (AI bot).
Changes in v2:
  - Remove unnecessary max_stack_depth assignment (Eduard).
  - Fix and test incorrect handling of private stacks.
  - Add veristat metric (Eduard).
====================

Link: https://patch.msgid.link/cover.1778700777.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>