[clang] [clang-tools-extra] [clangd] Support #embed highlighting in clangd (PR #212036)

[Aaron Ballman via cfe-commits]

AaronBallman wrote:

> Clangd does not send semantic tokens for any other preprocessor directives (`#define`, `#ifdef`, `#include`...), leaving those to client-side highlighting. I think it shouldn't be sending semantic tokens for `#embed` either.

I can definitely understand not doing just `embed` by itself, but is there a reason we want to leave the preprocessor to the client side? I can imagine that gets awkward for things like `module` which may or may not be handled by the preprocessor. Is there a reason we wouldn't want to handle all preprocessor directives at once?

https://github.com/llvm/llvm-project/pull/212036