[llvm-branch-commits] [llvm] AMDGPU: Add subtarget feature for memory atomic fadd f64 (PR #96444)

[Matt Arsenault via llvm-branch-commits]

arsenm wrote:

### Merge activity

* **Jul 10, 8:37 AM EDT**: @arsenm started a stack merge that includes this pull request via [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/96444).


https://github.com/llvm/llvm-project/pull/96444