nir: Handle all array stride cases in nir_deref_instr_array_stride

nir: Handle all array stride cases in nir_deref_instr_array_stride

This renames it to drop the ptr_as and makes it handle all of the stride
cases.  There's a bit of a tricky bit in here around Booleans but we
currently use 32-bit for those always.

Reviewed-by: Jesse Natalie <jenatali@microsoft.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6472>