Re: [PATCH v2] io_uring: add support for probing opcodes

[Mark Papadakis <markuspapadakis@icloud.com>]

I 've been thinking about this earlier.
I think the most realistic solution would be to have kind of website/page(libiouring.org?), which lists all SQE OPs, the kernel release that first implemented support for it, and (if necessary) notes about compatibility.

- There will be, hopefully, a lot more such OPS implemented in the future
- By having this list readily available, one can determine the lowest Linux Kernel release required(target) for a specific set of OPs they need for their program. If I want support for readv, writev, accept, and connect - say - then I should be able to quickly figure out that e.g 5.5 is the minimum LK release I must require
- Subtle issues may be discovered, or other such important specifics may be to be called out -- e.g readv works for < 5.5 for disk I/O but (e.g) "broken" for 5.4.3. This should be included in that table

Testing against specific SQE OPs support alone won't be enough, and it will likely also get convoluted fast.
liburing could provide a simple utility function that returns the (major, minor) LK release for convenience.

@markpapadakis