[llvm] [RISCV] Use vsetvli instead of vlenb in Prologue/Epilogue (PR #113756)

[Kito Cheng via llvm-commits]

kito-cheng wrote:

Put few more check in `RISCVFrameLowering::canUseAsPrologue` (which is used when doing shrink wrapping) to make sure no VL and VTYPE livein, but I can't make a testcase for that after I try 20 mins...

https://github.com/llvm/llvm-project/pull/113756