[clang] [llvm] AMDGPU: Move enqueued block handling into clang (PR #128519)

[Matt Arsenault via cfe-commits]

arsenm wrote:

### Merge activity

* **Mar 10, 8:52 AM EDT**: A user started a stack merge that includes this pull request via [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/128519).


https://github.com/llvm/llvm-project/pull/128519