[llvm] [RISCV][VSETVLI] Prefer VTYPE for immediate known to be less than VLMAX (PR #69759)

[Philip Reames via llvm-commits]

preames wrote:

As pointed out by @lukel97 , the transform proposed is invalid per the specification wording.  Going to take another look at these cases, but will clearly have to come at it from another angle.  

https://github.com/llvm/llvm-project/pull/69759