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

src/compiler/bytecode-graph-builder.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/bytecode-graph-builder.h"
 
 #include "src/compiler/linkage.h"
 #include "src/compiler/operator-properties.h"
 #include "src/interpreter/bytecode-array-iterator.h"
 
@@ skipping 394 matching lines @@
   return result;
 }
 
 
 Node* BytecodeGraphBuilder::MergeControl(Node* control, Node* other) {
   int inputs = control->op()->ControlInputCount() + 1;
   if (control->opcode() == IrOpcode::kLoop) {
     // 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);
     Node* merge_inputs[] = {control, other};
     control = graph()->NewNode(op, arraysize(merge_inputs), merge_inputs, true);
   }
   return control;
 }
 
 
 void BytecodeGraphBuilder::UpdateControlDependencyToLeaveFunction(Node* exit) {
   if (environment()->IsMarkedAsUnreachable()) return;
   environment()->MarkAsUnreachable();
   exit_controls_.push_back(exit);
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8