Hey folks.
First draft updating some references to the Unicode standard (and more
importantly replacing ISO-10646).
I'm hoping to get early feedback :)

https://isocpp.org/files/papers/D2736R0.pdf

A careful examination of the 3 standards do not reveal anything I think we
should be concerned about besides what I've highlighted in the paper but
please let me know if you have specific questions we need to address.

I would like to point out the mess that is __STDC_ISO_10646__. and whose
value currently depends on an ISO-10646 version.
In the paper I propose to make that value implementation-defined as it
cannot be relied upon except to check if some piece of code has been
updated in the past 20+ years.

I've also reworded the deprecated codecvt facilities to not mention UCS-2
and getting rid of one more reference.

I've massaged a few places to improve how we reference unicode properties.
The other thing that is not 100% clear to me is whether we should reference
UAX44, the Derived Core properties and UAX 29 (which we do currently),
or if referencing the Unicode standard implies all of that (I think it
does).

I've noticed that the Unicode standard incorrectly references version 14.0
of itself when it means 15.0 but hopefully we understand what is meant.

Thanks,
Corentin