[clang] [clang][ASTImporter] skip TemplateTypeParmDecl in VisitTypeAliasTemplateDecl (PR #74919)

[Balázs Kéri via cfe-commits]

balazske wrote:

> 
> Is import of `Callable` should be failed? I compiled this code
> 
> ```c++
> struct S;
> template <typename, typename>
> using Callable = S;
> template <typename>
> using Callable = S;
> ```
> 
> and clang report an error.

Yes the test was not exact, with the new code this import should fail.

https://github.com/llvm/llvm-project/pull/74919