[libcxx] [llvm] [libc++] Updates Unicode tables to Unicode 18 (PR #199111)

[Corentin Jabot via llvm-commits]

cor3ntin wrote:

Hum, this does actually update llvm tables in addition to libc++'s. Can you make a separate PR for that? Thanks

https://github.com/llvm/llvm-project/pull/199111