Currently, the index of SWMMAC builtins is of type `short`, likely based
on the
assumption that K can only be up to 32, meaning there are only 16
non-zero
elements. However, this is not future-proof. This patch updates all of
them to
`int`.
The intrinsics themselves don't need to be updated since they accept any
integer
type, and in the backend, they are already extended to 32-bit.
Additionally, the
tests already use various kinds of integers.
Partially fixes SWDEV-518183.
746d8b0740