[Isolates] Pass current isolate address to the regexp native functions

src/interpreter-irregexp.cc

 // Copyright 2008 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 145 matching lines @@
       // If the cache is not empty reuse the previously allocated stack.
       data_ = isolate->irregexp_interpreter_backtrack_stack_cache();
       isolate->set_irregexp_interpreter_backtrack_stack_cache(NULL);
     } else {
       // Cache was empty. Allocate a new backtrack stack.
       data_ = NewArray<int>(kBacktrackStackSize);
     }
   }
 
   ~BacktrackStack() {
-    Isolate* isolate = Isolate::Current();
-    if (isolate->irregexp_interpreter_backtrack_stack_cache() == NULL) {
+    if (isolate_->irregexp_interpreter_backtrack_stack_cache() == NULL) {
       // The cache is empty. Keep this backtrack stack around.
-      isolate->set_irregexp_interpreter_backtrack_stack_cache(data_);
+      isolate_->set_irregexp_interpreter_backtrack_stack_cache(data_);
     } else {
       // A backtrack stack was already cached, just release this one.
       DeleteArray(data_);
     }
   }
 
   int* data() const { return data_; }
 
   int max_size() const { return kBacktrackStackSize; }
 
@@ skipping 462 matching lines @@
     return RawMatch(isolate,
                     code_base,
                     subject_vector,
                     registers,
                     start_position,
                     previous_char);
   }
 }
 
 } }  // namespace v8::internal