[clang] [CIR][NFC] Add OGCG checks to OpenACC atomic tests (PR #190691)

[Erich Keane via cfe-commits]

https://github.com/erichkeane requested changes to this pull request.

We don't have OpenACC lowering in classic-codegen, so these tests aren't really adding anything.  

While I see this is useful for the development of the lowering, these tests aren't adding anything to the OpenACC coverage.

IF you have concerns that these 3 simple argument structures aren't going to be passed correctly in our lowering, you should make those a separate test.

https://github.com/llvm/llvm-project/pull/190691