[experiment] Improve loop algorithms crosschecking

The current technique use had a flaw. With algorithm containing
a different number of groups, it would truncate the to the shortest
as explained in the zip function documentation.

Now itertools.zip_longest is used to ensure that the iteration is
done on the longest input.
10 jobs for improve_loop_algorithm_crosscheck in 73 minutes and 51 seconds (queued for 1 second)