[clang] Qualify non-dependent types of a class template with its declaration (PR #67566)

[Luca Di sera via cfe-commits]

diseraluca wrote:

> > @vgvassilev If that is an acceptable interface for the LLVM interface then, yes, it would be perfect from our side, and I'm more than happy to update the PR in the next few days.
> > Just to be sure that I understood your proposal.
> > `getFullyQualified*` calls will accept a new parameter, a callable, that will be passed down the call chain up to `createNestedNameSpecifierForScopeOf(const ASTContext &, const Decl *, ...)` and will be called when the teplate case is encountered? Or are you thinking more of a callable that replaces the call to `createNestedNameSpecifierForScopeOf(const ASTContext &, const Decl *, ...)`?
> 
> I hesitate. Maybe we can pass a custom "policy" option and incorporate your code in there... We reiterate if the solution does not look good?

>From our point of view any solution is acceptable. But do note that  from our side it is not so much about incorporating custom code as much as removing that specific behavior at this point in time.

Could you expand about the policy? Are you talking about a "printing policy" or a custom policy for `getFullyQualified`?

https://github.com/llvm/llvm-project/pull/67566