[clang] [clang] Add code completion for #embed directive in C23 mode (PR #165550)

[Nathan Ridge via cfe-commits]

https://github.com/HighCommander4 requested changes to this pull request.

Thanks for the patch.

Could you add a test case as well? It looks like existing test coverage for preprocessor directive completions is found in [this file](https://searchfox.org/llvm/rev/3b30010303909efa01ac4d4fc018ad166e3b772d/clang/test/Index/complete-preprocessor.m). It's a bit of a weird test suite, but hopefully it should be clear from the existing test cases what the new one should look like; if not, I'm happy to go into more detail.

https://github.com/llvm/llvm-project/pull/165550