C++: constrain indirect out node to constructors

Author: Robert Marsh

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowUtil.qll

@@ -740,6 +740,7 @@ private predicate exprNodeShouldBeIndirectOperand(IndirectOperand node, Expr e,
 
 private predicate exprNodeShouldBeIndirectOutNode(IndirectArgumentOutNode node, Expr e) {
   exists(CallInstruction call |
+    call.getStaticCallTarget() instanceof Constructor and
     e = call.getConvertedResultExpression() and
     call.getThisArgumentOperand() = node.getAddressOperand()
   )