Delete the simulator when we don't need it anymore

src/isolate.h

 // Copyright 2012 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 371 matching lines @@
   // A thread has a PerIsolateThreadData instance for each isolate that it has
   // entered. That instance is allocated when the isolate is initially entered
   // and reused on subsequent entries.
   class PerIsolateThreadData {
    public:
     PerIsolateThreadData(Isolate* isolate, ThreadId thread_id)
         : isolate_(isolate),
           thread_id_(thread_id),
           stack_limit_(0),
           thread_state_(NULL),
-#if !defined(__arm__) && V8_TARGET_ARCH_ARM || \
-    !defined(__aarch64__) && V8_TARGET_ARCH_A64 || \
-    !defined(__mips__) && V8_TARGET_ARCH_MIPS
           simulator_(NULL),
-#endif
           next_(NULL),
           prev_(NULL) { }
+    ~PerIsolateThreadData();
     Isolate* isolate() const { return isolate_; }
     ThreadId thread_id() const { return thread_id_; }
 
     FIELD_ACCESSOR(uintptr_t, stack_limit)
     FIELD_ACCESSOR(ThreadState*, thread_state)
-
-#if !defined(__arm__) && V8_TARGET_ARCH_ARM || \
-    !defined(__aarch64__) && V8_TARGET_ARCH_A64 || \
-    !defined(__mips__) && V8_TARGET_ARCH_MIPS
     FIELD_ACCESSOR(Simulator*, simulator)
-#endif
 
     bool Matches(Isolate* isolate, ThreadId thread_id) const {
       return isolate_ == isolate && thread_id_.Equals(thread_id);
     }
 
    private:
     Isolate* isolate_;
     ThreadId thread_id_;
     uintptr_t stack_limit_;
     ThreadState* thread_state_;
-
-#if !defined(__arm__) && V8_TARGET_ARCH_ARM || \
-    !defined(__aarch64__) && V8_TARGET_ARCH_A64 || \
-    !defined(__mips__) && V8_TARGET_ARCH_MIPS
     Simulator* simulator_;
-#endif
 
     PerIsolateThreadData* next_;
     PerIsolateThreadData* prev_;
 
     friend class Isolate;
     friend class ThreadDataTable;
     friend class EntryStackItem;
 
     DISALLOW_COPY_AND_ASSIGN(PerIsolateThreadData);
   };
@@ skipping 1118 matching lines @@
   }
 
   EmbeddedVector<char, 128> filename_;
   FILE* file_;
   int scope_depth_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_ISOLATE_H_