Per-isolate v8::Locker and v8::Unlocker

src/arm/simulator-arm.h

Index: src/arm/simulator-arm.h
diff --git a/src/arm/simulator-arm.h b/src/arm/simulator-arm.h
index 40c9d6de20c20d52d7ceab9c4d3d93237957b778..391ef69f5efd62b213a7d14ab515c3feefbfe544 100644
--- a/src/arm/simulator-arm.h
+++ b/src/arm/simulator-arm.h
@@ -68,7 +68,9 @@ typedef int (*arm_regexp_matcher)(String*, int, const byte*, const byte*,
 // just use the C stack limit.
 class SimulatorStack : public v8::internal::AllStatic {
  public:
-  static inline uintptr_t JsLimitFromCLimit(uintptr_t c_limit) {
+  static inline uintptr_t JsLimitFromCLimit(v8::internal::Isolate* isolate,
+                                            uintptr_t c_limit) {
+    USE(isolate);
     return c_limit;
   }
 
@@ -143,7 +145,7 @@ class Simulator {
     num_d_registers = 16
   };
 
-  Simulator();
+  explicit Simulator(Isolate* isolate);
   ~Simulator();
 
   // The currently executing Simulator instance. Potentially there can be one
@@ -179,7 +181,7 @@ class Simulator {
   void Execute();
 
   // Call on program start.
-  static void Initialize();
+  static void Initialize(Isolate* isolate);
 
   // V8 generally calls into generated JS code with 5 parameters and into
   // generated RegExp code with 7 parameters. This is a convenience function,
@@ -408,8 +410,9 @@ class Simulator {
 // trouble down the line.
 class SimulatorStack : public v8::internal::AllStatic {
  public:
-  static inline uintptr_t JsLimitFromCLimit(uintptr_t c_limit) {
-    return Simulator::current(Isolate::Current())->StackLimit();
+  static inline uintptr_t JsLimitFromCLimit(v8::internal::Isolate* isolate,
+                                            uintptr_t c_limit) {
+    return Simulator::current(isolate)->StackLimit();
   }
 
   static inline uintptr_t RegisterCTryCatch(uintptr_t try_catch_address) {