[llvm] AMDGPU/GlobalISel: Disable LCSSA pass (PR #124297)

[Petar Avramovic via llvm-commits]

petar-avramovic wrote:

### Merge activity

* **Mar 12, 6:09 AM EDT**: A user started a stack merge that includes this pull request via [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/124297).


https://github.com/llvm/llvm-project/pull/124297