[clang] [Clang] Introduce scoped variants of GNU atomic functions (PR #72280)

[Joseph Huber via cfe-commits]

jhuber6 wrote:

> Is there any actual difference now between these and the HIP/OpenCL flavors other than dropping the language from the name?

Yes, these directly copy the GNU functions and names. The OpenCL / HIP ones use a different format.

https://github.com/llvm/llvm-project/pull/72280