selftests/bpf: add tests for stack_zero tracking

adjust two tests, since verifier got smarter
and add new one to test stack_zero logic

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
1 file changed