[clang] [clang][DebugInfo] Make fwd decl call site debug info consistent for methods (PR #222263)

[J. Ryan Stinnett via cfe-commits]

jryans wrote:

> How does the comment sound?

Comment looks good to me.

> > Would it make sense to push this logic into EmitFunctionDecl, or is that too complicated?
> 
> hrrrm, honestly I'm not sure, being not massively familiar with all the front end machinery. I had a quick look and it's probably ok to do that. However, I would naturally err on the side of keeping the change localised (as it is now) as I'm not confident. I can investigate more if you feel it's worth it though

I agree it's not entirely clear where it's best placed... While `EmitFunctionDecl` takes a similar action when `IsDeclForCallSite`, I suppose you may not need / want the rest of `EmitFunctionDecl` in your case...?

https://github.com/llvm/llvm-project/pull/222263