[clang] [Clang][Sema] Use correct TemplateName when transforming TemplateSpecializationType (PR #93411)

[Qizhi Hu via cfe-commits]

jcsxky wrote:

> The problem here is the loss of the qualification on the TemplateNames
> 
> This patch fixes the problem, without taking any workarounds: #93433
> 
> It also doesn't cause any change in diagnostics in `clang/test/SemaTemplate/typename-specifier-3.cpp`.

I think we should report this message since `B::arg` in `A<int>` is a NTTP.

https://github.com/llvm/llvm-project/pull/93411