[clang] [AMDGPU] Enable overriding of OpenCL's default address space (PR #117588)

[Alex Voicu via cfe-commits]

https://github.com/AlexVlx requested changes to this pull request.

In principle I am against this, it adds a relatively brittle hook, and bypasses the pre-existing mechanisms (use CL2 or enable the generic-as extension) for obtaining this behaviour, in a way that does not ensure that the pre-existing mechanisms are available (e.g. it appears one could pass the option, without asking for the generic as extension on CL3.0).

https://github.com/llvm/llvm-project/pull/117588