[clang] [clang-format] Correctly annotate token-pasted function decl names (PR #142337)

[Owen Pan via cfe-commits]

owenca wrote:

@prj- I understand. If you use `AlignFunctionDeclarations`, you might see formatting changes as the first token in a token-pasted function decl name was not annotated correctly before this patch.

https://github.com/llvm/llvm-project/pull/142337