In particular:
* Fix and extend the support for constructing possibly nested ArrayAttrs
from lists of Python ints. This can probably be generalized further
and used in many more places.
* Add arguments for `pad_to_multiple_of` and `copy_back_op`.
* Format with black and reorder (keyword-only) arguments to match
tablegen and (`*_gen.py`) order.
* Extend tests for new features.
Reviewed By: springerm
Differential Revision: https://reviews.llvm.org/D157789