[PATCH] bpf, x32: Fix bug with ALU64 {LSH, RSH, ARSH} BPF_X shift by 0

[Wang YanQing <udknight@xxxxxxxxx>]

commit 68a8357ec15bdce55266e9fba8b8b3b8143fa7d2 upstream.

The fix only affects x32 bpf jit, and it is critical to use x32 bpf jit on a
unpatched system, so I think we should backport it to the only affected stable
kernel version: v4.19

Thanks.

Cc: <stable@xxxxxxxxxxxxxxx> #4.19

Signed-off-by: Wang YanQing <udknight@xxxxxxxxx>