[llvm] AMDGPU: Directly select minimumnum/maximumnum with ieee_mode=0 (PR #141903)

[Matt Arsenault via llvm-commits]

arsenm wrote:

### Merge activity

* **Jun 17, 3:25 PM UTC**: A user started a stack merge that includes this pull request via [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/141903).


https://github.com/llvm/llvm-project/pull/141903