Implement optional turbofan UnalignedLoad and UnalignedStore operators

src/mips/assembler-mips.h

Index: src/mips/assembler-mips.h
diff --git a/src/mips/assembler-mips.h b/src/mips/assembler-mips.h
index f098bb4553a180d5e6c37cd5d3c8f86f43f8a2e1..869e1c60af8eacb18c68a7a9064bd99d17c62c15 100644
--- a/src/mips/assembler-mips.h
+++ b/src/mips/assembler-mips.h
@@ -1154,6 +1154,9 @@ class Assembler : public AssemblerBase {
   // Load Scaled Address instruction.
   void lsa(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.
@@ -1351,8 +1354,6 @@ class Assembler : public AssemblerBase {
   void GenInstrJump(Opcode opcode,
                      uint32_t address);
 
-  // Helpers.
-  void LoadRegPlusOffsetToAt(const MemOperand& src);
 
   // Labels.
   void print(Label* L);