Try standard library hardening

[Nerixyz]

LLVM's libc++ was the first to introduce hardening. Hardening will add extra checks for preconditions to some methods (e.g. element access in a vector) and terminate. We use libc++ on macOS right now. Hardening can be enabled for one program (or even more granular) without worrying about ABI or taking huge performance hits (docs).

It was since adopted to C++ 26, but isn't strictly tied to that standard version (i.e. it can be enabled in all standards). MSVC's STL is also working on hardening (likely to be in the next VS version).

I think we should try to run with the "fast" mode in nightly. This way we can find more subtle bugs.