C++ refactoring: ak.broadcast_arrays

[ioanaif]

No description provided.

[codecov]

Codecov Report

Merging #1368 (768b292) into main (b2fd2be) will increase coverage by 0.07%.
The diff coverage is 56.89%.

Impacted Files	Coverage Δ
src/awkward/_v2/_connect/cling.py	0.00% <0.00%> (ø)
src/awkward/_v2/_connect/pyarrow.py	85.74% <0.00%> (ø)
src/awkward/_v2/_lookup.py	97.50% <0.00%> (ø)
src/awkward/_v2/_prettyprint.py	66.09% <0.00%> (+2.29%)	⬆️
src/awkward/_v2/_typetracer.py	69.14% <0.00%> (ø)
src/awkward/_v2/forms/form.py	90.06% <0.00%> (ø)
src/awkward/_v2/identifier.py	55.69% <0.00%> (ø)
src/awkward/_v2/index.py	83.59% <0.00%> (ø)
src/awkward/_v2/operations/convert/ak_from_jax.py	75.00% <0.00%> (ø)
src/awkward/_v2/operations/convert/ak_to_jax.py	75.00% <0.00%> (ø)
... and 146 more

[jpivarski]

Great as-is, but maybe move test_broadcast_arrays before pytest.importorskip("numexpr") to make sure it gets tested (this one only depends on NumPy, not numexpr).

Go ahead and merge when ready.