Add `xsimd::arange_batch_constant`

[AntoinePrv]

While adding too many utilities for batch_constant may not be a goal, I believe an additional utility to generate a batch_constant with increasing numbers from zeros could be an interesting building block for a few cases:

• Lane mask: arange_batch_constant<T, A>() / make_batch_constant<T, size / 2, A>();
• Even numbers mask: arange_batch_constant<T, A>() % make_batch_constant<T, 2, A>();
• Already used in tests

[serge-sans-paille]

And why not: overload interaction with std::integral_constant, to avoid some tedious construction.

1. I can handle all those, that would be quite fun for me
2. let's postpone that after the release