selftests/bpf: add precision tracking test

Copy-paste of existing test
"calls: cross frame pruning - liveness propagation"
but ran with different parentage chain heuristic
which stresses different path in precision tracking logic.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>