[llvm] [RISCV] Allow vsetvlis with same register AVL in doLocalPostpass (PR #76801)

[Luke Lau via llvm-commits]

lukel97 wrote:

Just noticed, the commit message doesn't seem to have the PR body in it. Not sure what happened: I just clicked the squash and merge button.

https://github.com/llvm/llvm-project/pull/76801