[clang] [RFC] [clang] [CodeGen] Avoid creating global variable repeatedly when type are not specified (PR #114948)

[John McCall via cfe-commits]

rjmccall wrote:

I don't think there's any situation in which Clang needs to change the address space of a declaration.  It can happen if the programmer has declarations that disagree about the address space in which the entity is defined, but it's fair to just emit an error in  that situation.

https://github.com/llvm/llvm-project/pull/114948