[llvm] [RFC] Memory Model Relaxation Annotations (PR #78569)

[Pierre van Houtryve via llvm-commits]

Pierre-vh wrote:

I refactored the API a bit to remove the "builder" aspect. It's not really needed and just adds an unnecessary constraint on the class (which needed a `std::string` to own the strings in case `addTag` is called w/ a temp value).

https://github.com/llvm/llvm-project/pull/78569