[llvm] [RISCV] Fixed redundant add instructions generated during the fold of vscale add in rvv. (PR #225266)

[Min-Yih Hsu via llvm-commits]

mshockwave wrote:

> should I focus only on existing issues?

Existing issues could be a good starting point, but that's not the only way to contribute. If you found anything yourself that could be helpful to the broader community feel free to send a patch.

https://github.com/llvm/llvm-project/pull/225266