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

[Joseph Huber via llvm-commits]

jhuber6 wrote:

The issue was related to any use of global constructors, because those come from an externally initialized array of function pointers given to us by the linker. That affects HIP asan, OpenMP ctors / dtors, and the `libc` test suite.

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