[turbofan] Cleanup Graph and related classes.

test/unittests/compiler/graph-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 "src/compiler/graph.h"
 #include "src/compiler/graph-reducer.h"
+#include "src/compiler/node.h"
 #include "src/compiler/operator.h"
 #include "test/unittests/test-utils.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
 using testing::_;
 using testing::DefaultValue;
 using testing::Return;
 using testing::Sequence;
 using testing::StrictMock;
 
@@ skipping 97 matching lines @@
   EXPECT_CALL(r3, Reduce(node0)).InSequence(s1, s2, s3).WillOnce(
       Return(Reducer::Changed(node0)));
   EXPECT_CALL(r1, Reduce(node0)).InSequence(s1);
   EXPECT_CALL(r2, Reduce(node0)).InSequence(s2);
   ReduceNode(node0, &r1, &r2, &r3);
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8