[llvm] [CodeGen] Update for scalable MemoryType in MMO (PR #70452)

[David Green via llvm-commits]

davemgreen wrote:

I was thinking that would depend on whether the number of vector elements is assumed to always be the same between MMO and load type. i.e. the MMO could just store the size of the loaded memory, the load might extend each vector element. I'm not sure if there are somehow times when the types do not match?

https://github.com/llvm/llvm-project/pull/70452