Fix template copy constructor in zone_allocator

src/zone-allocator.h

 // Copyright 2014 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 32 matching lines @@
   typedef T value_type;
   typedef size_t size_type;
   typedef ptrdiff_t difference_type;
   template<class O> struct rebind {
     typedef zone_allocator<O> other;
   };
 
   explicit zone_allocator(Zone* zone) throw() : zone_(zone) {}
   explicit zone_allocator(const zone_allocator& other) throw()
       : zone_(other.zone_) {}
-  template<typename U> zone_allocator(const zone_allocator<U>&) throw() {}
+  template<typename U> zone_allocator(const zone_allocator<U>& other) throw()
+      : zone_(other.zone_) {}
+  template<typename U> friend class zone_allocator;
 
   pointer address(reference x) const {return &x;}
   const_pointer address(const_reference x) const {return &x;}
 
   pointer allocate(size_type count, const void* hint = 0) {
     size_t size = count * sizeof(value_type);
     size = RoundUp(size, kPointerSize);
     return static_cast<pointer>(zone_->New(size));
   }
   void deallocate(pointer p, size_type) { /* noop for Zones */ }
 
   size_type max_size() const throw() {
     size_type max = static_cast<size_type>(-1) / sizeof(T);
     return (max > 0 ? max : 1);
   }
   void construct(pointer p, const T& val) {
     new(static_cast<void*>(p)) T(val);
   }
   void destroy(pointer p) { (static_cast<T*>(p))->~T(); }
 
  private:
+  zone_allocator();
   Zone* zone_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_ZONE_ALLOCATOR_H_