[clang] [Clang][RFC] Intrododuce a builtin to determine the structure binding size (PR #131515)

[via cfe-commits]

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@@ -5389,6 +5389,15 @@ void CXXNameMangler::mangleExpression(const Expr *E, unsigned Arity,
       Diags.Report(DiagID);
       return;
     }
+    case UETT_StructuredBindingSize:
+      Out << "u11__builtin_structured_binding_size";
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halbi2 wrote:

```suggestion
      Out << "u33__builtin_structured_binding_size";
```

https://github.com/llvm/llvm-project/pull/131515