[llvm] [RISCV][GISEL] Add IRTranslation for shufflevector on scalable vector types (PR #80378)

[Craig Topper via llvm-commits]

topperc wrote:

> How would you otherwise distinguish between integer and float splats? If a splat vector only gets an immediate?

How do we do it for a BUILD_VECTOR of immediates?

https://github.com/llvm/llvm-project/pull/80378