coccinelle: misc: add array_size_dup script to detect missed overflow checks

Detect an opencoded expression that is used before or after
array_size()/array3_size()/struct_size() to compute the same size.

Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>