Opt compiler: ARM64: Follow other archs for a few codegen stubs.

Code generation for HInstanceFieldGet, HInstanceFieldSet,
HStaticFieldGet, and HStaticFieldSet are refactored to follow the
structure used for other backends.

Change-Id: I34a3bd17effa042238c6bf199848cbc2ec26ac5d
diff --git a/compiler/optimizing/code_generator_arm64.h b/compiler/optimizing/code_generator_arm64.h
index 07c6dd0..9fe60b8 100644
--- a/compiler/optimizing/code_generator_arm64.h
+++ b/compiler/optimizing/code_generator_arm64.h
@@ -159,6 +159,8 @@
   void GenerateMemoryBarrier(MemBarrierKind kind);
   void GenerateSuspendCheck(HSuspendCheck* instruction, HBasicBlock* successor);
   void HandleBinaryOp(HBinaryOperation* instr);
+  void HandleFieldSet(HInstruction* instruction, const FieldInfo& field_info);
+  void HandleFieldGet(HInstruction* instruction, const FieldInfo& field_info);
   void HandleShift(HBinaryOperation* instr);
   void GenerateImplicitNullCheck(HNullCheck* instruction);
   void GenerateExplicitNullCheck(HNullCheck* instruction);
@@ -185,8 +187,10 @@
 
  private:
   void HandleBinaryOp(HBinaryOperation* instr);
-  void HandleShift(HBinaryOperation* instr);
+  void HandleFieldSet(HInstruction* instruction);
+  void HandleFieldGet(HInstruction* instruction);
   void HandleInvoke(HInvoke* instr);
+  void HandleShift(HBinaryOperation* instr);
 
   CodeGeneratorARM64* const codegen_;
   InvokeDexCallingConventionVisitor parameter_visitor_;