Neither ___bpf_prog_run nor the JITs accept it.
Also adds a new test case.

Fixes: 17a52670 ("bpf: verifier (add verifier core)")
Signed-off-by: NEdward Cree <ecree@solarflare.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>