Added first shot at a development shell

src/smart-pointer.h

 // 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 68 matching lines @@
     T* temp = p;
     p = NULL;
     return temp;
   }
 
 
   // Assignment requires an empty (NULL) SmartPointer as the receiver.  Like
   // the copy constructor it removes the pointer in the original to avoid
   // double freeing.
   inline SmartPointer& operator=(const SmartPointer<T>& rhs) {
-    ASSERT(p == NULL);
+    ASSERT(is_empty());
     T* tmp = rhs.p;  // swap to handle self-assignment
     const_cast<SmartPointer<T>&>(rhs).p = NULL;
     p = tmp;
     return *this;
   }
 
 
+  inline bool is_empty() {
+    return p == NULL;
+  }
+
+
  private:
   T* p;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_SMART_POINTER_H_