[llvm] Riscv branch peephole opt (PR #90451)

[Craig Topper via llvm-commits]

topperc wrote:

Is this a widespread problem? In my local testing I see 2 places in perlbench.

Do you expect a performance gain from fixing this on perlbench?

I'm hesitant to add a new pass for a problem that occurs twice if it doesn't improve performance.

https://github.com/llvm/llvm-project/pull/90451