[clang] [clang] fix transformation of SubstNonTypeTemplateParmExpr nodes from type alias templates and concepts (PR #200850)

[Matheus Izvekov via cfe-commits]

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@@ -1496,6 +1496,12 @@ class DeclRefExpr final
     setDependence(computeDependence(this, Context));
   }
 
+  /// This DeclRefExpr is parenthesized as if it were written in parentheses,
+  /// e.g., "(x)". This is used in replacement expressions produced from
+  /// canonical template arguments.
+  bool isParenthesized() const { return DeclRefExprBits.IsParenthesized; }
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mizvekov wrote:

Wait, never mind, we do support it as an extension already, unlike GCC. https://compiler-explorer.com/z/fq1dvzb6W
This could be one of those warnings that turns into an error in a SFNIAE context, I will double check.

https://github.com/llvm/llvm-project/pull/200850