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

[Erich Keane via cfe-commits]

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@@ -307,7 +307,7 @@ static UnsignedOrNone EvaluateFoldExpandedConstraintSize(
   UnsignedOrNone NumExpansions = FE->getNumExpansions();
   if (S.CheckParameterPacksForExpansion(
           FE->getEllipsisLoc(), Pattern->getSourceRange(), Unexpanded, MLTAL,
-          Expand, RetainExpansion, NumExpansions) ||
+          true, Expand, RetainExpansion, NumExpansions) ||
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erichkeane wrote:

This needs a 'comment' on the `true` of the form: `/*argName=*/`

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