[Turbofan] Allow compiler to elide complex aliasing code.

src/register-configuration.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_COMPILER_REGISTER_CONFIGURATION_H_
 #define V8_COMPILER_REGISTER_CONFIGURATION_H_
 
 #include "src/base/macros.h"
 #include "src/machine-type.h"
 
@@ skipping 20 matching lines @@
 
   // Architecture independent maxes.
   static const int kMaxGeneralRegisters = 32;
   static const int kMaxFPRegisters = 32;
 
   static const RegisterConfiguration* ArchDefault(CompilerSelector compiler);
 
   RegisterConfiguration(int num_general_registers, int num_double_registers,
                         int num_allocatable_general_registers,
                         int num_allocatable_double_registers,
-                        AliasingKind fp_aliasing_kind,
                         const int* allocatable_general_codes,
                         const int* allocatable_double_codes,
+                        AliasingKind fp_aliasing_kind,
                         char const* const* general_names,
                         char const* const* float_names,
                         char const* const* double_names);
 
   int num_general_registers() const { return num_general_registers_; }
   int num_float_registers() const { return num_float_registers_; }
   int num_double_registers() const { return num_double_registers_; }
   int num_allocatable_general_registers() const {
     return num_allocatable_general_registers_;
   }
@@ skipping 50 matching lines @@
   bool AreAliases(MachineRepresentation rep, int index,
                   MachineRepresentation other_rep, int other_index) const;
 
  private:
   const int num_general_registers_;
   int num_float_registers_;
   const int num_double_registers_;
   int num_allocatable_general_registers_;
   int num_allocatable_double_registers_;
   int num_allocatable_float_registers_;
-  AliasingKind fp_aliasing_kind_;
   int32_t allocatable_general_codes_mask_;
   int32_t allocatable_double_codes_mask_;
   const int* allocatable_general_codes_;
   const int* allocatable_double_codes_;
   int allocatable_float_codes_[kMaxFPRegisters];
+  AliasingKind fp_aliasing_kind_;
   char const* const* general_register_names_;
   char const* const* float_register_names_;
   char const* const* double_register_names_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_REGISTER_CONFIGURATION_H_