[gcc r16-3720] libstdc++: Rename _CwFixedValue::_S_type member

[Jonathan Wakely]

https://gcc.gnu.org/g:39c003c0ecd4fcaf801e923b85e921327fd0d5d3

commit r16-3720-g39c003c0ecd4fcaf801e923b85e921327fd0d5d3
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Tue Sep 9 13:57:54 2025 +0100

    libstdc++: Rename _CwFixedValue::_S_type member
    
    Rename _S_type to __type as it's not a static member.
    
    Also rename _Tp to _Xv because it's not a type.
    
    libstdc++-v3/ChangeLog:
    
            * include/std/type_traits (_CwFixedValue::_S_type): Rename to
            __type.
            (constant_wrapper): Rename template parameter in declaration to
            match later definition.

Diff:
---
 libstdc++-v3/include/std/type_traits | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits
index 42a1e7f1732b..77ebb7e2c2f9 100644
--- a/libstdc++-v3/include/std/type_traits
+++ b/libstdc++-v3/include/std/type_traits
@@ -4307,19 +4307,19 @@ template<typename _Ret, typename _Fn, typename... _Args>
   template<typename _Tp>
     struct _CwFixedValue
     {
-      using _S_type = _Tp;
+      using __type = _Tp;
 
       constexpr
-      _CwFixedValue(_S_type __v) noexcept
+      _CwFixedValue(__type __v) noexcept
       : _M_data(__v) { }
 
-      _S_type _M_data;
+      __type _M_data;
     };
 
   template<typename _Tp, size_t _Extent>
     struct _CwFixedValue<_Tp[_Extent]>
     {
-      using _S_type = _Tp[_Extent];
+      using __type = _Tp[_Extent];
 
       constexpr
       _CwFixedValue(_Tp (&__arr)[_Extent]) noexcept
@@ -4338,8 +4338,8 @@ template<typename _Ret, typename _Fn, typename... _Args>
   template<typename _Tp, size_t _Extent>
     _CwFixedValue(_Tp (&)[_Extent]) -> _CwFixedValue<_Tp[_Extent]>;
 
-  template<_CwFixedValue _Tp,
-	   typename = typename decltype(_CwFixedValue(_Tp))::_S_type>
+  template<_CwFixedValue _Xv,
+	   typename = typename decltype(_CwFixedValue(_Xv))::__type>
     struct constant_wrapper;
 
   template<typename _Tp>
@@ -4653,7 +4653,7 @@ template<typename _Ret, typename _Fn, typename... _Args>
   {
     static constexpr const auto& value = _Xv._M_data;
     using type = constant_wrapper;
-    using value_type = typename decltype(_Xv)::_S_type;
+    using value_type = typename decltype(_Xv)::__type;
 
     template<_ConstExprParam _Right>
       constexpr auto