[llvm] [AMDGPU] Add AMDGPU-specific module splitting (PR #89245)

[Jeffrey Byrnes via llvm-commits]

jrbyrnes wrote:

> These nondeterministic results show up when AMDGPUSplitModule or SplitModule are used for partitioning

I ran into https://llvm.org/docs/CodingStandards.html#beware-of-non-determinism-due-to-ordering-of-pointers a while ago, and thought I'd point it out since I see this work uses sets/maps with pointer keys. Not sure if the iteration on these effects test output, but something to consider..

https://github.com/llvm/llvm-project/pull/89245