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

test/unittests/compiler/graph-reducer-unittest.cc

Index: test/unittests/compiler/graph-reducer-unittest.cc
diff --git a/test/unittests/compiler/graph-reducer-unittest.cc b/test/unittests/compiler/graph-reducer-unittest.cc
index 599af72983a53bc0068d9b3a4efebeac40aea24a..8d05c526c3a0b1498442aa41e2ce98393cd788ca 100644
--- a/test/unittests/compiler/graph-reducer-unittest.cc
+++ b/test/unittests/compiler/graph-reducer-unittest.cc
@@ -5,6 +5,7 @@
 #include "src/compiler/common-operator.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/node.h"
+#include "src/compiler/node-properties.h"
 #include "src/compiler/operator.h"
 #include "test/unittests/compiler/graph-reducer-unittest.h"
 #include "test/unittests/test-utils.h"
@@ -63,15 +64,15 @@ class InPlaceABReducer final : public Reducer {
     switch (node->op()->opcode()) {
       case kOpcodeA0:
         EXPECT_EQ(0, node->InputCount());
-        node->set_op(&kOpB0);
+        NodeProperties::ChangeOp(node, &kOpB0);
         return Replace(node);
       case kOpcodeA1:
         EXPECT_EQ(1, node->InputCount());
-        node->set_op(&kOpB1);
+        NodeProperties::ChangeOp(node, &kOpB1);
         return Replace(node);
       case kOpcodeA2:
         EXPECT_EQ(2, node->InputCount());
-        node->set_op(&kOpB2);
+        NodeProperties::ChangeOp(node, &kOpB2);
         return Replace(node);
     }
     return NoChange();
@@ -178,15 +179,15 @@ class InPlaceBCReducer final : public Reducer {
     switch (node->op()->opcode()) {
       case kOpcodeB0:
         EXPECT_EQ(0, node->InputCount());
-        node->set_op(&kOpC0);
+        NodeProperties::ChangeOp(node, &kOpC0);
         return Replace(node);
       case kOpcodeB1:
         EXPECT_EQ(1, node->InputCount());
-        node->set_op(&kOpC1);
+        NodeProperties::ChangeOp(node, &kOpC1);
         return Replace(node);
       case kOpcodeB2:
         EXPECT_EQ(2, node->InputCount());
-        node->set_op(&kOpC2);
+        NodeProperties::ChangeOp(node, &kOpC2);
         return Replace(node);
     }
     return NoChange();