[clang] [llvm] [OpenMP] Introduce the ompx_name clause for kernel naming (PR #200301)

[Johannes Doerfert via cfe-commits]

jdoerfert wrote:

> I don't like a lot of the custom handling here, I would expect this to have almost identical behavior to GNU-style variable renaming, i.e..
> 
> ```c
> int foo(void) asm("custom_name");
> ```

The user has no way of knowing the name right now. So they can't rename it either.

https://github.com/llvm/llvm-project/pull/200301