[clang] [Clang] Fix 'counted_by' for nested struct pointers (PR #110497)

[Bill Wendling via cfe-commits]

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@@ -1095,6 +1095,8 @@ class StructAccessBase
     return Visit(E->getBase());
   }
   const Expr *VisitCastExpr(const CastExpr *E) {
+    if (E->getCastKind() == CK_LValueToRValue)
+      return E;
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bwendling wrote:

It might be a good sanity check, though I think I've only seen an `LValueToRValue` cast before the node we wanted.

https://github.com/llvm/llvm-project/pull/110497