[clang] [clang-tools-extra] [clang][refactor] Refactor `findNextTokenIncludingComments` (PR #123060)

[Shafik Yaghmour via cfe-commits]

https://github.com/shafik commented:

`Lexer::findNextToken` has an additional check:

`if (!Lexer::isAtEndOfMacroExpansion(Loc, SM, LangOpts, &Loc))`

Does this not change behavior in the case we are replacing? I imagine folks just copied from `Lexer::findNextToken` and purposely left this out, is that wrong?

https://github.com/llvm/llvm-project/pull/123060