Put type attributes after class keyword

[dim]

Summary

Compiling <functional> in C++17 or higher mode results in:

functional:2500:1: warning: attribute '__visibility__' is ignored, place it after "class" to apply attribute to type declaration [-Wignored-attributes]
_LIBCPP_TYPE_VIS
^
__config:701:46: note: expanded from macro '_LIBCPP_TYPE_VIS'
#    define _LIBCPP_TYPE_VIS __attribute__ ((__visibility__("default")))
                                             ^
1 warning generated.

Fix it by putting the attribute after the class keyword.

include/functional

while (true)
          }
     }
 }
 
 #if _LIBCPP_STD_VER > 14
 
 // default searcher
 template<class _ForwardIterator, class _BinaryPredicate = equal_to<>>
-_LIBCPP_TYPE_VIS
-class default_searcher {
+class _LIBCPP_TYPE_VIS default_searcher {
 public:
     _LIBCPP_INLINE_VISIBILITY
     default_searcher(_ForwardIterator __f, _ForwardIterator __l, 
                        _BinaryPredicate __p = _BinaryPredicate())
         : __first_(__f), __last_(__l), __pred_(__p) {}
 
     template <typename _ForwardIterator2>
     _LIBCPP_INLINE_VISIBILITY