[SYCL][DOC] Spec for discard queue events

[alexanderfle]

See extension document for SYCL describing discard queue events behaviour

[Pennycook]

@alexanderfle Apologies, I didn't mean to mark this as ready to review. My finger slipped, and I can't find a way to mark the PR as a draft again.

[alexanderfle]

@Pennycook , @gmlueck , @romanovvlad, are there any other comments on the current version of the document?
Сan we open the draft for review?

[Pennycook]

Spotted one formatting issue during another read through. I think this can be opened for review.

[alexanderfle]

@gmlueck , btw, Should we add to the document that Level Zero will temporarily work without optimization? Since Level Zero support is required to be able to not create a low-level event.

[gmlueck]

@gmlueck , btw, Should we add to the document that Level Zero will temporarily work without optimization? Since Level Zero support is required to be able to not create a low-level event.

This depends. Do we plan to implement the Level Zero support at the same time that we implement the DPC++ support? If so, there is no need to document that limitation because it won't exist when this extension is implemented.

[alexanderfle]

This depends. Do we plan to implement the Level Zero support at the same time that we implement the DPC++ support? If so, there is no need to document that limitation because it won't exist when this extension is implemented.

Ok, I expect DPC ++ support to be added faster than Level Zero plugin support. So I'll add a few words about that.

[gmlueck]

LGTM