[turbofan] Cleanup Graph and related classes.

test/unittests/compiler/value-numbering-reducer-unittest.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 <limits>
 
 #include "src/compiler/graph.h"
+#include "src/compiler/node.h"
+#include "src/compiler/operator.h"
 #include "src/compiler/value-numbering-reducer.h"
 #include "test/unittests/test-utils.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 struct TestOperator : public Operator {
   TestOperator(Operator::Opcode opcode, Operator::Properties properties,
                size_t value_in, size_t value_out)
@@ skipping 103 matching lines @@
 
 TEST_F(ValueNumberingReducerTest, WontReplaceNodeWithItself) {
   Node* n = graph()->NewNode(&kOp0);
   EXPECT_FALSE(Reduce(n).Changed());
   EXPECT_FALSE(Reduce(n).Changed());
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8