[turbofan] removed some dead code.

src/compiler/register-allocator.h

 // 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.
 
 #ifndef V8_REGISTER_ALLOCATOR_H_
 #define V8_REGISTER_ALLOCATOR_H_
 
 #include "src/compiler/instruction.h"
 #include "src/ostreams.h"
 #include "src/register-configuration.h"
@@ skipping 401 matching lines @@
 
   static const int kInvalidSize = -1;
   static const float kInvalidWeight;
   static const float kMaxWeight;
 
  private:
   friend class TopLevelLiveRange;
   explicit LiveRange(int relative_id, MachineRepresentation rep,
                      TopLevelLiveRange* top_level);
 
-  void AppendAsChild(TopLevelLiveRange* other);
   void UpdateParentForAllChildren(TopLevelLiveRange* new_top_level);
 
   void set_spilled(bool value) { bits_ = SpilledField::update(bits_, value); }
 
   UseInterval* FirstSearchIntervalForPosition(LifetimePosition position) const;
   void AdvanceLastProcessedMarker(UseInterval* to_start_of,
                                   LifetimePosition but_not_past) const;
 
   typedef BitField<bool, 0, 1> SpilledField;
   typedef BitField<int32_t, 6, 6> AssignedRegisterField;
@@ skipping 166 matching lines @@
 
   bool IsSpilledOnlyInDeferredBlocks() const {
     return spilled_in_deferred_blocks_;
   }
 
   struct SpillMoveInsertionList;
 
   SpillMoveInsertionList* spill_move_insertion_locations() const {
     return spill_move_insertion_locations_;
   }
-  void set_last_child(LiveRange* range) { last_child_ = range; }
-  LiveRange* last_child() const { return last_child_; }
   TopLevelLiveRange* splinter() const { return splinter_; }
   void SetSplinter(TopLevelLiveRange* splinter) {
     DCHECK_NULL(splinter_);
     DCHECK_NOT_NULL(splinter);
 
     splinter_ = splinter;
     splinter->relative_id_ = GetNextChildId();
     splinter->set_spill_type(spill_type());
     splinter->SetSplinteredFrom(this);
   }
@@ skipping 15 matching lines @@
   union {
     // Correct value determined by spill_type()
     InstructionOperand* spill_operand_;
     SpillRange* spill_range_;
   };
   SpillMoveInsertionList* spill_move_insertion_locations_;
   // TODO(mtrofin): generalize spilling after definition, currently specialized
   // just for spill in a single deferred block.
   bool spilled_in_deferred_blocks_;
   int spill_start_index_;
-  LiveRange* last_child_;
   UsePosition* last_pos_;
   TopLevelLiveRange* splinter_;
   bool has_preassigned_slot_;
 
   DISALLOW_COPY_AND_ASSIGN(TopLevelLiveRange);
 };
 
 
 struct PrintableLiveRange {
   const RegisterConfiguration* register_configuration_;
@@ skipping 498 matching lines @@
   RegisterAllocationData* const data_;
 
   DISALLOW_COPY_AND_ASSIGN(LiveRangeConnector);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_REGISTER_ALLOCATOR_H_