[llvm] [mlir] [mlir][OpenMP] Add __atomic_store to AtomicInfo (PR #121055)

[via llvm-commits]

NimishMishra wrote:

@tblah / @Meinersbur The PR https://github.com/llvm/llvm-project/pull/134455 will take a while to land; I was following the discussion Michael had at EuroLLVM (which he has summarized on the PR). 

The two issues fixed by this PR are blockers for removing the experimental status on OpenMP : https://github.com/llvm/llvm-project/issues/110008. Is it okay if we go ahead with merging this PR before LLVM branches out this year ?

https://github.com/llvm/llvm-project/pull/121055