[clang] [clang] Implement P2582R1: CTAD from inherited constructors (PR #98788)

[via cfe-commits]

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@@ -11758,6 +11795,40 @@ static void DiagnoseBadDeduction(Sema &S, NamedDecl *Found, Decl *Templated,
       return;
     }
 
+    // Errors in deduction guides from inherited constructors
+    // will present as substitution failures in the mapping
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antangelo wrote:

I've updated the comment. `Mapping` here refers to the partial specialization that maps the return type of the original deduction guide back to the derived class

https://github.com/llvm/llvm-project/pull/98788