[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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@@ -316,6 +330,13 @@ TemplateNameKind Sema::isTemplateName(Scope *S,
     }
   }
 
+  if (isPackProducingBuiltinTemplateName(Template) &&
+      S->getTemplateParamParent() == nullptr) {
+    Diag(Name.getBeginLoc(), diag::err_builtin_pack_outside_template);
+    // Recover by returning the template, even though we would never be able to
+    // substitute it.
+  }
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ilya-biryukov wrote:

Done.

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