[Mlir-commits] [mlir] [mlir][arith] fix wrong floordivsi fold (#83079) (PR #83248)

[Jacob Yu]

pingshiyu wrote:

> @pingshiyu would you be able to review the correctness of this change?

sure, I've just taken some time to check through the cases, lgtm re correctness. 

thanks @lipracer!

maybe some extra tests would be nice for the edge cases, e.g. `floordivsi(min_val, 1)`, and `floordivsi(max_val, -1)`

https://github.com/llvm/llvm-project/pull/83248