[llvm] [LV] Remove common extends and selects in CSE (PR #147731)

[David Sherwood via llvm-commits]

david-arm wrote:

Looks like one of the tests is failing:

```
/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/Transforms/LoopVectorize/RISCV/vectorize-force-tail-with-evl-fixed-order-recurrence.ll:635:16: error: IF-EVL-NEXT: expected string not found in input
```

https://github.com/llvm/llvm-project/pull/147731