x32: bpf: implement jitting of JMP32

This patch implements code-gen for new JMP32 instructions on x32.
Also fixed several reverse xmas tree coding style issues as I am there.

Cc: Wang YanQing <udknight@gmail.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>