Add a higher-level test (C BPF program) for the new functionality -
variable access stack reads and writes.
Signed-off-by: NAndrei Matei <andreimatei1@gmail.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210207011027.676572-5-andreimatei1@gmail.com