[clang] ✨ [Sema, Lex, Parse] Preprocessor embed in C and C++ (and Obj-C and Obj-C++ by-proxy) (PR #68620)

[Aaron Ballman via cfe-commits]

AaronBallman wrote:

> @AaronBallman, hope the WG14 meeting went well? I've essentially done what I planned to do here, so I was wondering if you're ready to take it from here? I can try to incorporate the review feedback myself, but it's quite likely I'd make a mess of it (not familiar with the clang code base at all). 😅

Thank you! I hope to pick this up soon-ish (I'm still trying to dig out from under my review backlog at the moment). I'm hoping to have time to dedicate to it so this gets in before the holiday season. As a backup plan, @Fznamznon is also willing to help out if I'm not able to get to it soon enough, but she's currently working on constexpr issues. So this is staying hot on my radar, but it may be a month+ before it gets picked up due to other pressures.

https://github.com/llvm/llvm-project/pull/68620