Adds ldr and str to arm64.

runtime/vm/simulator_arm64.h

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // Declares a Simulator for ARM64 instructions if we are not generating a native
 // ARM64 binary. This Simulator allows us to run and debug ARM64 code generation
 // on regular desktop machines.
 // Dart calls into generated code by "calling" the InvokeDartCode stub,
 // which will start execution in the Simulator or forwards to the real entry
 // on a ARM64 HW platform.
@@ skipping 90 matching lines @@
   // Registered breakpoints.
   Instr* break_pc_;
   int64_t break_instr_;
 
   // Illegal memory access support.
   static bool IsIllegalAddress(uword addr) {
     return addr < 64*1024;
   }
   void HandleIllegalAccess(uword addr, Instr* instr);
 
+  // Handles an unaligned memory access.
+  void UnalignedAccess(const char* msg, uword addr, Instr* instr);
+
   // Handles a legal instruction that the simulator does not implement.
   void UnimplementedInstruction(Instr* instr);
 
   // Unsupported instructions use Format to print an error and stop execution.
   void Format(Instr* instr, const char* format);
 
+  inline uint8_t ReadBU(uword addr);
+  inline int8_t ReadB(uword addr);
+  inline void WriteB(uword addr, uint8_t value);
+
+  inline uint16_t ReadHU(uword addr, Instr* instr);
+  inline int16_t ReadH(uword addr, Instr* instr);
+  inline void WriteH(uword addr, uint16_t value, Instr* instr);
+
+  inline uint32_t ReadWU(uword addr, Instr* instr);
+  inline int32_t ReadW(uword addr, Instr* instr);
+  inline void WriteW(uword addr, uint32_t value, Instr* instr);
+
+  inline intptr_t ReadX(uword addr, Instr* instr);
+  inline void WriteX(uword addr, intptr_t value, Instr* instr);
+
   // Helper functions to set the conditional flags in the architecture state.
   void SetNZFlagsW(int32_t val);
   bool CarryFromW(int32_t left, int32_t right);
   bool BorrowFromW(int32_t left, int32_t right);
   bool OverflowFromW(
       int32_t alu_out, int32_t left, int32_t right, bool addition);
 
   void SetNZFlagsX(int64_t val);
   bool CarryFromX(int64_t left, int64_t right);
   bool BorrowFromX(int64_t left, int64_t right);
@@ skipping 24 matching lines @@
 
   // Executes ARM64 instructions until the PC reaches kEndSimulatingPC.
   void Execute();
 
   DISALLOW_COPY_AND_ASSIGN(Simulator);
 };
 
 }  // namespace dart
 
 #endif  // VM_SIMULATOR_ARM64_H_