Adds Runtime call stub and Dart entry stub to ARM64.

runtime/vm/simulator_arm64.h

Index: runtime/vm/simulator_arm64.h
===================================================================
--- runtime/vm/simulator_arm64.h	(revision 35155)
+++ runtime/vm/simulator_arm64.h	(working copy)
@@ -22,6 +22,7 @@
 namespace dart {
 
 class Isolate;
+class SimulatorSetjmpBuffer;
 
 class Simulator {
  public:
@@ -41,6 +42,7 @@
   int32_t get_wregister(Register reg, R31Type r31t = R31IsUndef) const;
 
   int64_t get_pc() const;
+  int64_t get_last_pc() const;
   void set_pc(int64_t pc);
 
   // Accessor to the internal simulator stack top.
@@ -65,6 +67,18 @@
                int64_t parameter2,
                int64_t parameter3);
 
+  // Runtime and native call support.
+  enum CallKind {
+    kRuntimeCall,
+    kLeafRuntimeCall,
+    kLeafFloatRuntimeCall,
+    kBootstrapNativeCall,
+    kNativeCall
+  };
+  static uword RedirectExternalReference(uword function,
+                                         CallKind call_kind,
+                                         int argument_count);
+
   void Longjmp(uword pc,
                uword sp,
                uword fp,
@@ -91,11 +105,13 @@
   bool v_flag_;
 
   // Simulator support.
+  int64_t last_pc_;
   int64_t pc_;
   char* stack_;
   bool pc_modified_;
   intptr_t icount_;
   static int64_t flag_stop_sim_at_;
+  SimulatorSetjmpBuffer* last_setjmp_buffer_;
   uword top_exit_frame_info_;
 
   // Registered breakpoints.
@@ -162,6 +178,8 @@
 
   bool ConditionallyExecute(Instr* instr);
 
+  void DoRedirectedCall(Instr* instr);
+
   // Decode instructions.
   void InstructionDecode(Instr* instr);
   #define DECODE_OP(op)                                                        \
@@ -172,7 +190,16 @@
   // Executes ARM64 instructions until the PC reaches kEndSimulatingPC.
   void Execute();
 
+  // Longjmp support for exceptions.
+  SimulatorSetjmpBuffer* last_setjmp_buffer() {
+    return last_setjmp_buffer_;
+  }
+  void set_last_setjmp_buffer(SimulatorSetjmpBuffer* buffer) {
+    last_setjmp_buffer_ = buffer;
+  }
+
   friend class SimulatorDebugger;
+  friend class SimulatorSetjmpBuffer;
   DISALLOW_COPY_AND_ASSIGN(Simulator);
 };