add regtest for ippinfo
(more to come)

Signed-off-by: etienne <etienne.basset@ensta.org>
remove ip6.n8, useless
add a block(ip6, block_number)  macro

Signed-off-by: etienne <etienne.basset@ensta.org>
use block() macro instead of touching ip6.n16

Signed-off-by: etienne <etienne.basset@ensta.org>
use block MACRO instead of touching ip6.n16

Signed-off-by: etienne <etienne.basset@ensta.org>