[llvm] [AMDGPU] Re-enable closed-world assumption as an opt-out feature (PR #115371)

[Joseph Huber via llvm-commits]

jhuber6 wrote:

> I'm not sure that is related. Essentially what you are describing is ABI linking, which is not officially supported. That's why we only allow RDC for those programming models we support, and in RDC mode I don't think it's gonna happen.

"ABI" linking works just fine for globals, it's only an issue for functions and functions that reference LDS. We still define global constructors in "non-RDC" mode, the distinction isn't really important once we're at the backend.

https://github.com/llvm/llvm-project/pull/115371