[clang] [Clang][Interp] Visit `DecompositionDecl` and create a local variable (PR #100400)

[Timm Baeder via cfe-commits]

================
@@ -5234,6 +5240,9 @@ bool Compiler<Emitter>::visitDeclRef(const ValueDecl *D, const Expr *E) {
           return false;
         };
 
+        if (isa<DecompositionDecl>(VD))
----------------
tbaederr wrote:

```suggestion
       // DecompositionDecls are just proxies for us.
        if (isa<DecompositionDecl>(VD))
```

https://github.com/llvm/llvm-project/pull/100400