[clang] [clang-tools-extra] [clang] Implement CWG2398 provisional TTP matching to class templates (PR #94981)

[via cfe-commits]

================
@@ -9219,7 +9222,8 @@ class Sema final : public SemaBase {
   /// \returns true if an error occurred, false otherwise.
   bool CheckTemplateArgumentList(
       TemplateDecl *Template, SourceLocation TemplateLoc,
-      TemplateArgumentListInfo &TemplateArgs, bool PartialTemplateArgs,
+      TemplateArgumentListInfo &TemplateArgs,
----------------
cor3ntin wrote:

```cpp

bool CheckTemplateArgumentList(
      TemplateDecl *Template, SourceLocation TemplateLoc,
      TemplateArgumentListInfo &TemplateArgs,
      bool PartialTemplateArgs,
      SmallVectorImpl<TemplateArgument> &SugaredConverted,
      SmallVectorImpl<TemplateArgument> &CanonicalConverted,
      bool UpdateArgsWithConversions = true,
      bool *ConstraintsNotSatisfied = nullptr, bool PartialOrderingTTP = false, const DefaultArguments * DefaultArgs = nullptr);


bool CheckTemplateArgumentList(
      TemplateDecl *Template, SourceLocation TemplateLoc,
      TemplateArgumentListInfo &TemplateArgs,
      const DefaultArguments & DefaultArgs, 
      SmallVectorImpl<TemplateArgument> &SugaredConverted,
      SmallVectorImpl<TemplateArgument> &CanonicalConverted) {

return CheckTemplateArgumentList(Template, TemplateLoc, /*PartialTemplateArgs=*/false,
                                                                  SugaredConverted, CanonicalConverted, /*UpdateArgsWithConversions=*/true, nullptr, false, &DefaultArgs); 
                                                                 
}
```

Maybe something like that?

https://github.com/llvm/llvm-project/pull/94981