[clang] Fix codegen of consteval functions returning an empty class. (PR #93115)

[Eli Friedman via cfe-commits]

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@@ -135,6 +135,17 @@ class AggExprEmitter : public StmtVisitor<AggExprEmitter> {
     EnsureDest(E->getType());
 
     if (llvm::Value *Result = ConstantEmitter(CGF).tryEmitConstantExpr(E)) {
+      // An empty record can overlap other data (if declared with
+      // no_unique_address); omit the store for such types - as there is no
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efriedma-quic wrote:

See what, exactly?  Given the derived class, computing the address of the base class doesn't take any instructions, because it's the same address.

https://github.com/llvm/llvm-project/pull/93115