[clang] [clang][SPIR-V] Addrspace of opencl_global should always be 1 (PR #136753)

[Alex Voicu via cfe-commits]

https://github.com/AlexVlx approved this pull request.

LGTM, thanks! FWIW, perhaps it'd be worthwhile (as a follow-up, not here) to simply make the DefIsGen AS map correct/valid, and replace the dummy bits?

https://github.com/llvm/llvm-project/pull/136753