[clang] [clang-tools-extra] [Clang] Add a builtin that deduplicate types into a pack (PR #106730)

[Ilya Biryukov via cfe-commits]

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@@ -5857,6 +5900,29 @@ bool Sema::CheckTemplateArgumentList(
       }
     }
 
+    // Check for builtins producing template packs at this position, we do not
+    // support them yet.
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ilya-biryukov wrote:

Done.

https://github.com/llvm/llvm-project/pull/106730