[clang] [libclc] [llvm] [openmp] [Clang] `__attribute__((assume))` refactor (PR #84934)

[Romaric Jodin via cfe-commits]

rjodinchr wrote:

> > It has nothing to do with OpenMP. The goal was just to get something in the llvm IR that we could check for. The `assume` attribute allows us to pass a string that we can then check in a llvm pass.
> 
> Could you investigate whether 'annotate' would do what you want? IIRC, the point of it is to just pass a string onto the AST/IR.

At the moment, I did not manage to have annotation working. It's because annotation is an indirect link to the function. Thus it does not stick around when I link modules.

Maybe the easiest way would be to add a real attribute for clspv?

https://github.com/llvm/llvm-project/pull/84934