[llvm] [AArch64] Add bitcasts for lowering saturating add/sub and shift intrinsics. (PR #161840)

[Paul Walker via llvm-commits]

paulwalker-arm wrote:

> are you fine with generalizing the intrinsics to allow for floating point types

The IR must remain type clear and so we should not allow floating point types for intrinsically integer operations.

https://github.com/llvm/llvm-project/pull/161840