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

[via cfe-commits]

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@@ -172,6 +180,13 @@ class SubstTemplateTemplateParmPackStorage : public UncommonTemplateNameStorage,
                       unsigned Index, bool Final);
 };
 
+struct DefaultArguments {
+  unsigned StartPos;
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cor3ntin wrote:

Can we add a comment here?

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