[libc++] Remove non-standard member type iterator_type from __wrap_iter (#186871)

Resolves #186801 
Removed the non-standard member type `iterator_type` from `__wrap_iter`.
This member exposed the underlying iterator type, and its removal
prevents users from relying on the implementation detail.

libcxx/docs/ReleaseNotes/23.rst

diff --git a/libcxx/docs/ReleaseNotes/23.rst b/libcxx/docs/ReleaseNotes/23.rst
index 4441a8a..9fcb0bbe 100644
--- a/libcxx/docs/ReleaseNotes/23.rst
+++ b/libcxx/docs/ReleaseNotes/23.rst
@@ -55,8 +55,8 @@
 - The ``std::launch::any`` enumerator that was accidentally provided as an extension is now deprecated.
   It will be removed in LLVM 25.
 
-- ``__wrap_iter``'s (iterator type for ``array``, ``span``, ``string``, ``string_view`` and ``vector``) ``base()``
-  method has been removed as it was non-standard.
+- In ``__wrap_iter`` (iterator wrapper type for ``array``, ``span``, ``string``, ``string_view`` and ``vector``), 
+  the ``base()`` method and ``iterator_type`` member type have been removed as they are non-standard.
 
 Potentially breaking changes
 ----------------------------

libcxx/include/__iterator/wrap_iter.h

diff --git a/libcxx/include/__iterator/wrap_iter.h b/libcxx/include/__iterator/wrap_iter.h
index c1b27b8..576adfb 100644
--- a/libcxx/include/__iterator/wrap_iter.h
+++ b/libcxx/include/__iterator/wrap_iter.h
@@ -34,18 +34,17 @@
 template <class _Iter>
 class __wrap_iter {
 public:
-  typedef _Iter iterator_type;
-  typedef typename iterator_traits<iterator_type>::value_type value_type;
-  typedef typename iterator_traits<iterator_type>::difference_type difference_type;
-  typedef typename iterator_traits<iterator_type>::pointer pointer;
-  typedef typename iterator_traits<iterator_type>::reference reference;
-  typedef typename iterator_traits<iterator_type>::iterator_category iterator_category;
+  typedef typename iterator_traits<_Iter>::value_type value_type;
+  typedef typename iterator_traits<_Iter>::difference_type difference_type;
+  typedef typename iterator_traits<_Iter>::pointer pointer;
+  typedef typename iterator_traits<_Iter>::reference reference;
+  typedef typename iterator_traits<_Iter>::iterator_category iterator_category;
 #if _LIBCPP_STD_VER >= 20
   typedef contiguous_iterator_tag iterator_concept;
 #endif
 
 private:
-  iterator_type __i_;
+  _Iter __i_;
 
   friend struct pointer_traits<__wrap_iter<_Iter> >;
 
@@ -103,7 +102,7 @@
   }
 
 private:
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit __wrap_iter(iterator_type __x) _NOEXCEPT : __i_(__x) {}
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit __wrap_iter(_Iter __x) _NOEXCEPT : __i_(__x) {}
 
   template <class _Up>
   friend class __wrap_iter;