[llvm-branch-commits] [RISCV] Port RISCVInsertVSETVLI to NewPM (PR #235407)

[Aiden Grossman via llvm-branch-commits]

https://github.com/boomanaiden154 created https://github.com/llvm/llvm-project/pull/235407

Standard NewPM pass porting. Use an Impl class to avoid teasing out all
the state in the original pass class.