[llvm] [RISCV] Change how MMO is rebuilt in lowerFixedLengthVectorLoadToRVV/lowerFixedLengthVectorStoreToRVV (PR #88811)

[David Green via llvm-commits]

davemgreen wrote:

Hi. Sorry for the bug and thanks for the fix. I think I missed that the typesize needed to be adjusted by the vscale range. The new code sounds good if its producing the right mmo sizes.

https://github.com/llvm/llvm-project/pull/88811