Initial patch for a64.

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index 6c797b252280a75680aa1f1c0f23cf58557d9f7e..1bf79623cc10010a7d6e35ad5e6492836d13676b 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -116,7 +116,9 @@ void ThreadLocalTop::InitializeInternal() {
 void ThreadLocalTop::Initialize() {
   InitializeInternal();
 #ifdef USE_SIMULATOR
-#ifdef V8_TARGET_ARCH_ARM
+#ifdef V8_TARGET_ARCH_A64
+  simulator_ = Simulator::current(isolate_);
+#elif V8_TARGET_ARCH_ARM
   simulator_ = Simulator::current(isolate_);
 #elif V8_TARGET_ARCH_MIPS
   simulator_ = Simulator::current(isolate_);
@@ -1625,7 +1627,9 @@ char* Isolate::RestoreThread(char* from) {
   // This might be just paranoia, but it seems to be needed in case a
   // thread_local_top_ is restored on a separate OS thread.
 #ifdef USE_SIMULATOR
-#ifdef V8_TARGET_ARCH_ARM
+#ifdef V8_TARGET_ARCH_A64
+  thread_local_top()->simulator_ = Simulator::current(this);
+#elif V8_TARGET_ARCH_ARM
   thread_local_top()->simulator_ = Simulator::current(this);
 #elif V8_TARGET_ARCH_MIPS
   thread_local_top()->simulator_ = Simulator::current(this);
@@ -1775,7 +1779,8 @@ Isolate::Isolate()
   thread_manager_ = new ThreadManager();
   thread_manager_->isolate_ = this;
 
-#if defined(V8_TARGET_ARCH_ARM) && !defined(__arm__) || \
+#if defined(V8_TARGET_ARCH_A64) && !defined(__arm__) || \
+    defined(V8_TARGET_ARCH_ARM) && !defined(__arm__) || \
     defined(V8_TARGET_ARCH_MIPS) && !defined(__mips__)
   simulator_initialized_ = false;
   simulator_i_cache_ = NULL;
@@ -2128,7 +2133,8 @@ bool Isolate::Init(Deserializer* des) {
 
   // Initialize other runtime facilities
 #if defined(USE_SIMULATOR)
-#if defined(V8_TARGET_ARCH_ARM) || defined(V8_TARGET_ARCH_MIPS)
+#if defined(V8_TARGET_ARCH_A64) || defined(V8_TARGET_ARCH_ARM) || \
+    defined(V8_TARGET_ARCH_MIPS)
   Simulator::Initialize(this);
 #endif
 #endif