[llvm] [llvm] Support building with c++23 (PR #154372)

[Kyle Krüger via llvm-commits]

kykrueger wrote:

> Oh, I mistakenly pressed the "Update branch" button. Feel free to force-push to fix the commit history.
> 
> (Formatting errors still need to be resolved.)

Looks like clang-format was missing from my system. 
They should all be resolved now.

https://github.com/llvm/llvm-project/pull/154372