[lldb] [llvm] [clang] [clang-tools-extra] [libc] [flang] [libcxx] [compiler-rt] ✨ [Sema, Lex, Parse] Preprocessor embed in C and C++ (and Obj-C and Obj-C++ by-proxy) (PR #68620)

[Vlad Serebrennikov via cfe-commits]

Endilll wrote:

There has been multiple discussion in different places about behavior of `-E`, `-M`, and friends (the most notable starts [here](https://discord.com/channels/636084430946959380/636732781086638081/1175241241710055424)), so I thought it would be a good idea to raise awareness among commonly used tools. `ccache`, `sccache`, and `distcc` are the ones I know that might be directly impacted by this.

https://github.com/ccache/ccache/discussions/1366
https://github.com/mozilla/sccache/discussions/1990
https://github.com/distcc/distcc/issues/494

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