[llvm] Attributor: Add baseline tests for propagating align to atomics (PR #134836)

[Matt Arsenault via llvm-commits]

arsenm wrote:

### Merge activity

* **Apr 8, 11:01 AM EDT**: A user started a stack merge that includes this pull request via [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/134836).


https://github.com/llvm/llvm-project/pull/134836