[turbofan] Rework Node guts to save space.

test/cctest/compiler/test-control-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/v8.h"
 #include "test/cctest/cctest.h"
 
 #include "src/base/bits.h"
 #include "src/compiler/all-nodes.h"
 #include "src/compiler/common-operator.h"
@@ skipping 846 matching lines @@
   }
 }
 
 
 TEST(CMergeReduce_dead_rm1b) {
   ControlReducerTester R;
 
   Node* t = R.graph.NewNode(R.common.IfTrue(), R.start);
   Node* f = R.graph.NewNode(R.common.IfTrue(), R.start);
   for (int i = 0; i < 2; i++) {
-    Node* merge = R.graph.NewNode(R.common.Merge(3), R.dead, R.dead, R.dead);
     for (int j = i + 1; j < 3; j++) {
+      Node* merge = R.graph.NewNode(R.common.Merge(3), R.dead, R.dead, R.dead);
       merge->ReplaceInput(i, t);
       merge->ReplaceInput(j, f);
       R.ReduceMerge(merge, merge);
       CheckMerge(merge, t, f);
     }
   }
 }
 
 
 TEST(CMergeReduce_dead_rm2) {
@@ skipping 753 matching lines @@
 
   R.ReduceGraph();  // d1 gets folded true.
 
   CheckInputs(ret, y2, R.start, R.start);
 
   DeadChecker dead(&R.graph);
   dead.Check(d1);
   dead.Check(d2);
   dead.Check(d3);
 }