Implement optional turbofan UnalignedLoad and UnalignedStore operators

src/mips64/assembler-mips64.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 1199 matching lines @@
     UNREACHABLE();
   }
 
   bool IsPrevInstrCompactBranch() { return prev_instr_compact_branch_; }
 
  protected:
   // Load Scaled Address instructions.
   void lsa(Register rd, Register rt, Register rs, uint8_t sa);
   void dlsa(Register rd, Register rt, Register rs, uint8_t sa);
 
+  // Helpers.
+  void LoadRegPlusOffsetToAt(const MemOperand& src);
+
   // Relocation for a type-recording IC has the AST id added to it.  This
   // member variable is a way to pass the information from the call site to
   // the relocation info.
   TypeFeedbackId recorded_ast_id_;
 
   inline static void set_target_internal_reference_encoded_at(Address pc,
                                                               Address target);
 
   int64_t buffer_space() const { return reloc_info_writer.pos() - pc_; }
 
@@ skipping 176 matching lines @@
       Opcode opcode, Register rs, int32_t offset21,
       CompactBranchType is_compact_branch = CompactBranchType::NO);
   void GenInstrImmediate(Opcode opcode, Register rs, uint32_t offset21);
   void GenInstrImmediate(
       Opcode opcode, int32_t offset26,
       CompactBranchType is_compact_branch = CompactBranchType::NO);
 
   void GenInstrJump(Opcode opcode,
                      uint32_t address);
 
-  // Helpers.
-  void LoadRegPlusOffsetToAt(const MemOperand& src);
-
   // Labels.
   void print(Label* L);
   void bind_to(Label* L, int pos);
   void next(Label* L, bool is_internal);
 
   // One trampoline consists of:
   // - space for trampoline slots,
   // - space for labels.
   //
   // Space for trampoline slots is equal to slot_count * 2 * kInstrSize.
@@ skipping 82 matching lines @@
  public:
   explicit EnsureSpace(Assembler* assembler) {
     assembler->CheckBuffer();
   }
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_ARM_ASSEMBLER_MIPS_H_