[turbofan] Make Node::set_op safer via wrapper.

src/compiler/bytecode-graph-builder.cc

Index: src/compiler/bytecode-graph-builder.cc
diff --git a/src/compiler/bytecode-graph-builder.cc b/src/compiler/bytecode-graph-builder.cc
index 10f44a677abd1c1df8301a7fe6e7ae2c346cdc76..2ee44d529ee48692c1d3688956bd9a8493ef81e9 100644
--- a/src/compiler/bytecode-graph-builder.cc
+++ b/src/compiler/bytecode-graph-builder.cc
@@ -412,12 +412,12 @@ Node* BytecodeGraphBuilder::MergeControl(Node* control, Node* other) {
     // Control node for loop exists, add input.
     const Operator* op = common()->Loop(inputs);
     control->AppendInput(graph_zone(), other);
-    control->set_op(op);
+    NodeProperties::ChangeOp(control, op);
   } else if (control->opcode() == IrOpcode::kMerge) {
     // Control node for merge exists, add input.
     const Operator* op = common()->Merge(inputs);
     control->AppendInput(graph_zone(), other);
-    control->set_op(op);
+    NodeProperties::ChangeOp(control, op);
   } else {
     // Control node is a singleton, introduce a merge.
     const Operator* op = common()->Merge(inputs);