[clang] [Clang][AMDGPU][Driver] Add `avail-extern-gv-in-addrspace-to-local` option when ThinTLO is enabled (PR #144914)

[Joseph Huber via cfe-commits]

https://github.com/jhuber6 approved this pull request.

Bit of a hack it seems, but better than it being broken.

https://github.com/llvm/llvm-project/pull/144914