[clang] [llvm] [flang] [NFC][AMDGPU] Move address space enum to LLVM directory (PR #73944)

[Sergio Afonso via cfe-commits]

https://github.com/skatrak commented:

Thanks for this work. I only have very little feedback, but it LGTM.

I think the enum looks a bit out of place in a file called "TargetParser.h", but I'm not very familiar with this part of the project, so I'll let the experts say something if there is a more suitable location for it.

https://github.com/llvm/llvm-project/pull/73944