Implement optional turbofan UnalignedLoad and UnalignedStore operators

src/mips64/assembler-mips64.h

Index: src/mips64/assembler-mips64.h
diff --git a/src/mips64/assembler-mips64.h b/src/mips64/assembler-mips64.h
index 0174fa44f91b33483d0125ce096edd45dda9dcf5..1cc3b176c5973f4ac816b38e6e33f02d2784f2d8 100644
--- a/src/mips64/assembler-mips64.h
+++ b/src/mips64/assembler-mips64.h
@@ -1209,6 +1209,9 @@ class Assembler : public AssemblerBase {
   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.
@@ -1405,9 +1408,6 @@ class Assembler : public AssemblerBase {
   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);