Revert of Reland: Remove register index/code indirection

src/lithium-allocator.h

 // Copyright 2012 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_LITHIUM_ALLOCATOR_H_
 #define V8_LITHIUM_ALLOCATOR_H_
 
 #include "src/allocation.h"
 #include "src/lithium.h"
 #include "src/zone.h"
@@ skipping 502 matching lines @@
   LPlatformChunk* chunk_;
 
   // During liveness analysis keep a mapping from block id to live_in sets
   // for blocks already analyzed.
   ZoneList<BitVector*> live_in_sets_;
 
   // Liveness analysis results.
   ZoneList<LiveRange*> live_ranges_;
 
   // Lists of live ranges
-  EmbeddedVector<LiveRange*, Register::kNumRegisters> fixed_live_ranges_;
-  EmbeddedVector<LiveRange*, DoubleRegister::kMaxNumRegisters>
+  EmbeddedVector<LiveRange*, Register::kMaxNumAllocatableRegisters>
+      fixed_live_ranges_;
+  EmbeddedVector<LiveRange*, DoubleRegister::kMaxNumAllocatableRegisters>
       fixed_double_live_ranges_;
   ZoneList<LiveRange*> unhandled_live_ranges_;
   ZoneList<LiveRange*> active_live_ranges_;
   ZoneList<LiveRange*> inactive_live_ranges_;
   ZoneList<LiveRange*> reusable_slots_;
 
   // Next virtual register number to be assigned to temporaries.
   int next_virtual_register_;
   int first_artificial_register_;
   GrowableBitVector double_artificial_registers_;
 
   RegisterKind mode_;
   int num_registers_;
-  const int* allocatable_register_codes_;
 
   BitVector* assigned_registers_;
   BitVector* assigned_double_registers_;
 
   HGraph* graph_;
 
   bool has_osr_entry_;
 
   // Indicates success or failure during register allocation.
   bool allocation_ok_;
@@ skipping 16 matching lines @@
   size_t allocator_zone_start_allocation_size_;
 
   DISALLOW_COPY_AND_ASSIGN(LAllocatorPhase);
 };
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_LITHIUM_ALLOCATOR_H_