selftests/bpf: test case for invalid call stack in dead code

This patch adds a test case with an excessive number of call stack frames
in dead code.

Signed-off-by: Paul Chaignon <paul.chaignon@orange.com>
Tested-by: Xiao Han <xiao.han@orange.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>