[turbofan] Remove locally constructed simplified builders.

src/compiler/simplified-lowering.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/simplified-lowering.h"
 
 #include <limits>
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
@@ skipping 1145 matching lines @@
 
 SimplifiedLowering::SimplifiedLowering(JSGraph* jsgraph, Zone* zone,
                                        SourcePositionTable* source_positions)
     : jsgraph_(jsgraph),
       zone_(zone),
       zero_thirtyone_range_(Type::Range(0, 31, zone)),
       source_positions_(source_positions) {}
 
 
 void SimplifiedLowering::LowerAllNodes() {
-  SimplifiedOperatorBuilder simplified(graph()->zone());
-  RepresentationChanger changer(jsgraph(), &simplified, jsgraph()->isolate());
+  RepresentationChanger changer(jsgraph(), jsgraph()->simplified(),
+                                jsgraph()->isolate());
   RepresentationSelector selector(jsgraph(), zone_, &changer,
                                   source_positions_);
   selector.Run(this);
 }
 
 
 Node* SimplifiedLowering::Untag(Node* node) {
   // TODO(titzer): factor this out to a TaggingScheme abstraction.
   Node* shift_amount = jsgraph()->Int32Constant(kSmiTagSize + kSmiShiftSize);
   return graph()->NewNode(machine()->WordSar(), node, shift_amount);
@@ skipping 507 matching lines @@
   ReplaceEffectUses(node, comparison);
   node->ReplaceInput(0, comparison);
   node->ReplaceInput(1, jsgraph()->SmiConstant(EQUAL));
   node->TrimInputCount(2);
   NodeProperties::ChangeOp(node, machine()->IntLessThanOrEqual());
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8