Merge branch 'bpf-core-fixes'

Andrii Nakryiko says:

====================
This patch set fixes bug in CO-RE relocation candidate finding logic, which
currently allows matching against forward declarations, functions, and other
named types, even though it makes no sense to even attempt. As part of
verifying the fix, add test using vmlinux.h with preserve_access_index
attribute and utilizing struct pt_regs heavily to trace nanosleep syscall
using 5 different types of tracing BPF programs.

This test also demonstrated problems using struct pt_regs in syscall
tracepoints and required a new set of macro, which were added in patch #3
into bpf_tracing.h.

Patch #1 fixes annoying issue with selftest failure messages being out of
sync.

v1->v2:
  - drop unused handle__probed() function (Martin).
====================

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>