[clang] [Clang] Implement P3034R1 Module Declarations Shouldn’t be Macros (PR #90574)

[via cfe-commits]

cor3ntin wrote:

> Thanks! I'd like to move the implementation from Parser to Preprocessor. I think It would make more sense to do these checks during lexing.

I'm not sure that would make a lot of sense (unless we were doing exactly how the specification does it, by injecting a token for a fully parsed module... but that does seem necessary).

Either way, the parsing of semi conlon/attributes should stay in the parser.

https://github.com/llvm/llvm-project/pull/90574