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

src/x64/simulator-x64.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 37 matching lines @@
   (FUNCTION_CAST<regexp_matcher>(entry)(p0, p1, p2, p3, p4, p5, p6, p7))
 
 #define TRY_CATCH_FROM_ADDRESS(try_catch_address) \
   (reinterpret_cast<TryCatch*>(try_catch_address))
 
 // The stack limit beyond which we will throw stack overflow errors in
 // generated code. Because generated code on x64 uses the C stack, we
 // 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(Isolate* isolate,
+                                            uintptr_t c_limit) {
     return c_limit;
   }
 
   static inline uintptr_t RegisterCTryCatch(uintptr_t try_catch_address) {
     return try_catch_address;
   }
 
   static inline void UnregisterCTryCatch() { }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_SIMULATOR_X64_H_