[libcxx-commits] [libcxx] [libc++][doc] Update the release notes for LLVM 18 (PR #78324)

[Will Hawkins via libcxx-commits]

https://github.com/hawkinsw commented:

Looks great. I hope that my suggestions are useful. Feel free to ignore if they aren't!

https://github.com/llvm/llvm-project/pull/78324