[llvm] [RISCV] Move RISCVInsertVSETVLI to after phi elimination (PR #91440)

[Luke Lau via llvm-commits]

lukel97 wrote:

@rofirrim thanks for reporting that, can you check if 9ae2177843f681c70ad89506155a2cb83eeebfd4 fixes it?

https://github.com/llvm/llvm-project/pull/91440