With NOPs padding, x64 jit now can handle the jump cases like
bpf_fill_maxinsns11().

Signed-off-by: Gary Lin <glin@suse.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210119102501.511-3-glin@suse.com