[llvm] [RFC] IR: Define noalias.addrspace metadata (PR #102461)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> Just a quick check: in the absence of the MD (neither the FE nor inference are deterministic when it comes to figuring out the concrete AS), we'd still fall back to the run time check on things like atomics on private, correct?

Yes. It will emit __builtin_amdgcn_is_private(x) { non_atomic_sequence; } else { do_real_atomic(x) } 

https://github.com/llvm/llvm-project/pull/102461