[llvm] [CodeGen] Port AtomicExpand to new Pass Manager (PR #71220)

[via llvm-commits]

paperchalice wrote:

> What's the rationale behind the pass renaming?

The naming convention in `PassRegistry.def` is inconsistent and there is no pass naming convention in LLVM coding standard. 
In `PassRegistry.def` there are 5 passes contains "expand" and 3 passes follow the `expand-*` convention.

https://github.com/llvm/llvm-project/pull/71220