[clang] [AST] Iterate redecls starting from the canonical one in getRawCommentsForAnyRedecl() (PR #108475)

[Younan Zhang via cfe-commits]

zyn0217 wrote:

> This is in turn because the [code that sets this](https://searchfox.org/llvm/rev/3ae71d154e5dfb5e5a5d27b3699b27ce2b55f44d/clang/lib/AST/Comment.cpp#238-243) is conditioned on FunctionDecl::getNumTemplateParameterLists() != 0.

I was curious why it is relying on `getNumTemplateParameterLists()`. To my understanding, it should call `FD->getTemplateSpecializationInfo()`, shouldn't it?

https://github.com/llvm/llvm-project/pull/108475