Remove an extra include from NullPtr.h

Source/wtf/NullPtr.h

 /*
 
 Copyright (C) 2010 Apple Inc. All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions
 are met:
 1.  Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.
 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 13 matching lines @@
 
 */
 
 #ifndef NullPtr_h
 #define NullPtr_h
 
 // For compilers and standard libraries that do not yet include it, this adds the
 // nullptr_t type and nullptr object. They are defined in the same namespaces they
 // would be in compiler and library that had the support.
 
-#include <ciso646>
-
 #if COMPILER_SUPPORTS(CXX_NULLPTR) || defined(_LIBCPP_VERSION)
 
 #include <cstddef>
 
 // libstdc++ supports nullptr_t starting with gcc 4.6. STLport doesn't define it.
 #if (defined(__GLIBCXX__) && __GLIBCXX__ < 20110325) || defined(_STLPORT_VERSION)
 namespace std {
 typedef decltype(nullptr) nullptr_t;
 }
 #endif
@@ skipping 32 matching lines @@
 #else
 #define WTF_DISALLOW_CONSTRUCTION_FROM_ZERO(ClassName) \
     private: \
         ClassName(int)
 #define WTF_DISALLOW_ZERO_ASSIGNMENT(ClassName) \
     private: \
         ClassName& operator=(int)
 #endif
 
 #endif