Revert "Remove BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION"

This reverts commit af136e483d.

include/boost/bind/arg.hpp

@@ -43,6 +43,7 @@ template< int I > bool operator==( arg<I> const &, arg<I> const & )
     return true;
 }
 
+#if !defined( BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION )
 
 template< int I > struct is_placeholder< arg<I> >
 {
@@ -54,6 +55,7 @@ template< int I > struct is_placeholder< arg<I> (*) () >
     enum _vt { value = I };
 };
 
+#endif
 
 } // namespace boost