CategoryAliases is for regexp to use, for things like \p{Letter} as an alias for \p{L}.
Cn and LC are special-case categories that were never implemented
but should have been.
These changes were generated by the updated generator in CL 641395.
Fixes #70780.
Change-Id: Ibba20ff76191c8ae9631ac5ba19965790fe0cc81
Reviewed-on: https://go-review.googlesource.com/c/go/+/641376
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Alan Donovan <adonovan@google.com>