[SYCL][DOC] Move sycl_ext_oneapi_clock

[KornevNikita]

The extension was enabled, moving to the experimental dir

[gmlueck]

Please update the Status text using the boilerplate here:

https://github.com/intel/llvm/blob/sycl/sycl/doc/extensions/template.asciidoc#status

[KornevNikita]

@gmlueck oh, right, updated. BTW could you please clarify - how do we define a status as experimental? OpenCL feature cl_khr_kernel_clock is finalized since v3.0.18. Since this feature doesn't use an experimental feature under the hood, should it also be marked as supported instead?

[gmlueck]

BTW could you please clarify - how do we define a status as experimental?

I could go either way on this one. When we first started the specification, it seemed like there were a lot of unresolved issues, and that was a good reason to keep it experimental. At this point, I think those issues have been resolved, though.

Do we have a specific customer/user who is asking for this one? Do we expect to get any feedback from them?

[github-actions]

@intel/llvm-gatekeepers please consider merging

[KornevNikita]

@gmlueck it's a request (CMPLRLLVM-50746) from syclomatic folks to create an alternative for cuda's clock(). Since we just introduced the feature, I believe they'll find some bugs/feedback to share. From this POV maybe we better keep it experimental until they verify it works as expected.

[github-actions]

@intel/llvm-gatekeepers please consider merging

[KornevNikita]

@intel/llvm-gatekeepers please merge