[llvm] [IA][RISCV] Add support for vp.load/vp.store with shufflevector (PR #135445)

[Luke Lau via llvm-commits]

https://github.com/lukel97 approved this pull request.

LGTM, I've left some nits and just some thoughts on possible follow ups, thanks for pushing this through

https://github.com/llvm/llvm-project/pull/135445