rsync + xxhash packages

[Ben RUBSON]

Hi,

New rsync version (3.2.x) brings a lot of interesting new features.

It then now depends on various libraries :
- openssl
- zstd
- lz4
- xxhash

Cygwin already has the first 3 ones.
But it lacks xxhash.

Would then be nice to have a Cygwin package for xxash, so that new rsync version could be flawlessly built with all the new features.
https://github.com/Cyan4973/xxHash

May I then ask, could one of the maintainers have a look into packaging this new library please ?

And when updating the rsync package (Jari Aalto ?), please properly link against the 4 above libraires ?

For my part, I plan to write a CI for rsync on Cygwin, as soon as xxash package will be available.

Thank you very much for your support,

Best regards,

Ben