[turbofan] remove spill slot reuse flag

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/zone-containers.h"
 
@@ skipping 385 matching lines @@
   void ResolvePhis();
 
   // Phase 3: compute liveness of all virtual register.
   void BuildLiveRanges();
   bool ExistsUseWithoutDefinition();
 
   // Phase 4: compute register assignments.
   void AllocateGeneralRegisters();
   void AllocateDoubleRegisters();
 
-  // Phase 5: reassign spill splots for maximal reuse.
-  void ReuseSpillSlots();
+  // Phase 5: assign spill splots.
+  void AssignSpillSlots();
 
   // Phase 6: commit assignment.
   void CommitAssignment();
 
   // Phase 7: compute values for pointer maps.
   void PopulatePointerMaps();  // TODO(titzer): rename to PopulateReferenceMaps.
 
   // Phase 8: reconnect split ranges with moves.
   void ConnectRanges();
 
@@ skipping 59 matching lines @@
   void ActiveToHandled(LiveRange* range);
   void ActiveToInactive(LiveRange* range);
   void InactiveToHandled(LiveRange* range);
   void InactiveToActive(LiveRange* range);
 
   // Helper methods for allocating registers.
   bool TryReuseSpillForPhi(LiveRange* range);
   bool TryAllocateFreeReg(LiveRange* range);
   void AllocateBlockedReg(LiveRange* range);
   SpillRange* AssignSpillRangeToLiveRange(LiveRange* range);
-  void FreeSpillSlot(LiveRange* range);
-  InstructionOperand* TryReuseSpillSlot(LiveRange* range);
 
   // Live range splitting helpers.
 
   // Split the given range at the given position.
   // If range starts at or after the given position then the
   // original range is returned.
   // Otherwise returns the live range that starts at pos and contains
   // all uses from the original range that follow pos. Uses at pos will
   // still be owned by the original range after splitting.
   LiveRange* SplitRangeAt(LiveRange* range, LifetimePosition pos);
@@ skipping 121 matching lines @@
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(RegisterAllocator);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_REGISTER_ALLOCATOR_H_