[clang] [Sema] Preserve ContainsUnexpandedParameterPack in TransformLambdaExpr (PR #86265)

[via cfe-commits]

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@@ -136,6 +155,11 @@ namespace {
     /// do not contain unexpanded parameter packs.
     bool TraverseStmt(Stmt *S) {
       Expr *E = dyn_cast_or_null<Expr>(S);
+
+      llvm::SaveAndRestore _(InConstraint);
+      if (CurrentFunction && CurrentFunction->getTrailingRequiresClause() == S)
+        InConstraint = true;
+
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cor3ntin wrote:

Do we have tests for a lambda (potentially constrained?) used in a requires clause of another function?

https://github.com/llvm/llvm-project/pull/86265