[llvm] [RISCV] Remove`riscv.segN.load/store` in favor of their mask variants (PR #137045)

[Harald van Dijk via llvm-commits]

hvdijk wrote:

> If we're just "expecting the backend to ignore them", then is it just a matter of adding pointer type overloads to the memory intrinsics?

Yes, it's just a matter of updating `llvm_ptr_ty` to `llvm_anyptr_ty` and the associated `IntrinsicTypes`, and updating the tests. It's simple enough but it's a large number of changes. I'm trying to get something working for that, hopefully I will be able to open a PR soon enough that we can skip the stopgap measure to avoid the crashes.

https://github.com/llvm/llvm-project/pull/137045