Merge branch 'Split bpf_sock dst_port field'

Jakub Sitnicki says:

====================

This is a follow-up to discussion around the idea of making dst_port in struct
bpf_sock a 16-bit field that happened in [1].

v2:
- use an anonymous field for zero padding (Alexei)

v1:
- keep dst_field offset unchanged to prevent existing BPF program breakage
  (Martin)
- allow 8-bit loads from dst_port[0] and [1]
- add test coverage for the verifier and the context access converter

[1] https://lore.kernel.org/bpf/87sftbobys.fsf@cloudflare.com/
====================

Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>