[turbofan] Cleanup Graph and related classes.

src/compiler/common-operator-reducer.cc

 // Copyright 2014 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/common-operator-reducer.h"
 
 #include "src/compiler/common-operator.h"
+#include "src/compiler/node.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 Reduction CommonOperatorReducer::Reduce(Node* node) {
   switch (node->opcode()) {
     case IrOpcode::kEffectPhi:
     case IrOpcode::kPhi: {
       int const input_count = node->InputCount();
@@ skipping 14 matching lines @@
     }
     default:
       break;
   }
   return NoChange();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8