[llvm] [CodeGenPrepare][RISCV] Combine (X ^ Y) and (X == Y) where appropriate (PR #130922)

[Sam Elliott via llvm-commits]

================
@@ -239,3 +239,85 @@ define i32 @oneusecmp(i32 %a, i32 %b, i32 %d) {
   %x = add i32 %s, %s2
   ret i32 %x
 }
+
+define i32 @xor_branch_imm_ret(i32 %x) {
----------------
lenary wrote:

```suggestion
define i32 @xor_branch_imm_ret(i32 %x) nounwind {
```

https://github.com/llvm/llvm-project/pull/130922