[clang] [llvm] [RISCV] Remove experimental from Ztso. (PR #96465)

[Philip Reames via cfe-commits]

preames wrote:

> I think @preames told me he was keeping this experimental for a reason.

Yes, revert pending.

The concern here is that there are multiple possible ABIs here, and at the point I implemented this, the ABI chosen in my initial set of patches was compatible with the then current WMO ABI, but is *incompatible* with the revised ABI for load acquire/store release.  I know there has been some work on this since, but the prominent warning comment has not been removed, and there is not discussion in this review about status.  

I will note that simply deleting a comment from the docs *which directly explain why something is still experimental* without discussing exactly that issue in the review thread is, IMO, poor behavior on all parties involved.  


https://github.com/llvm/llvm-project/pull/96465