Address ldionne's comments

Author: winner245

libcxx/include/list

@@ -342,10 +342,7 @@ public:
       : __base(__prev, __next) {}
   _LIBCPP_CONSTEXPR_SINCE_CXX26 _LIBCPP_HIDE_FROM_ABI ~__list_node() {}
 
-  _LIBCPP_CONSTEXPR_SINCE_CXX26 _LIBCPP_HIDE_FROM_ABI __base_pointer __as_link() {
-    return pointer_traits<__base_pointer>::pointer_to(
-        *static_cast<typename pointer_traits<__base_pointer>::element_type*>(std::addressof(*this)));
-  }
+  _LIBCPP_CONSTEXPR_SINCE_CXX26 _LIBCPP_HIDE_FROM_ABI __base_pointer __as_link() { return __base::__self(); }
 };
 
 template <class _Tp, class _Alloc = allocator<_Tp> >

libcxx/test/std/containers/sequences/list/list.cons/from_range.pass.cpp

@@ -27,7 +27,7 @@ TEST_CONSTEXPR_CXX26 bool test() {
 
   static_assert(test_constraints<std::list, int, double>());
 
-  if (!std::is_constant_evaluated()) {
+  if (!TEST_IS_CONSTANT_EVALUATED) {
     test_exception_safety_throwing_copy<std::list>();
     test_exception_safety_throwing_allocator<std::list, int>();
   }

libcxx/test/std/containers/sequences/list/list.cons/input_iterator.pass.cpp

@@ -174,7 +174,7 @@ TEST_CONSTEXPR_CXX26 void test_emplacable_concept_with_alloc() {
 #endif
 }
 
-void test_ctor_under_alloc() {
+TEST_CONSTEXPR_CXX26 void test_ctor_under_alloc() {
 #if TEST_STD_VER >= 11
   int arr1[] = {42};
   int arr2[] = {1, 101, 42};

libcxx/test/std/containers/sequences/list/list.modifiers/append_range.pass.cpp

@@ -32,7 +32,7 @@ TEST_CONSTEXPR_CXX26 bool test() {
   });
   test_sequence_append_range_move_only<std::list>();
 
-  if (!std::is_constant_evaluated()) {
+  if (!TEST_IS_CONSTANT_EVALUATED) {
     test_append_range_exception_safety_throwing_copy<std::list>();
     test_append_range_exception_safety_throwing_allocator<std::list, int>();
   }

libcxx/test/std/containers/sequences/list/list.modifiers/assign_range.pass.cpp

@@ -32,7 +32,7 @@ TEST_CONSTEXPR_CXX26 bool test() {
   });
   test_sequence_assign_range_move_only<std::list>();
 
-  if (!std::is_constant_evaluated()) {
+  if (!TEST_IS_CONSTANT_EVALUATED) {
     test_assign_range_exception_safety_throwing_copy<std::list>();
     test_assign_range_exception_safety_throwing_allocator<std::list, int>();
   }

libcxx/test/std/containers/sequences/list/list.modifiers/insert_range.pass.cpp

@@ -35,7 +35,7 @@ TEST_CONSTEXPR_CXX26 bool test() {
   });
   test_sequence_insert_range_move_only<std::list>();
 
-  if (!std::is_constant_evaluated()) {
+  if (!TEST_IS_CONSTANT_EVALUATED) {
     test_insert_range_exception_safety_throwing_copy<std::list>();
     test_insert_range_exception_safety_throwing_allocator<std::list, int>();
   }

libcxx/test/std/containers/sequences/list/list.modifiers/prepend_range.pass.cpp

@@ -32,7 +32,7 @@ TEST_CONSTEXPR_CXX26 bool test() {
   });
   test_sequence_prepend_range_move_only<std::list>();
 
-  if (!std::is_constant_evaluated()) {
+  if (!TEST_IS_CONSTANT_EVALUATED) {
     test_prepend_range_exception_safety_throwing_copy<std::list>();
     test_prepend_range_exception_safety_throwing_allocator<std::list, int>();
   }

libcxx/test/std/containers/sequences/list/list.modifiers/push_back_rvalue.pass.cpp

@@ -10,7 +10,7 @@
 
 // <list>
 
-// void push_back(value_type&& x); // constexpr since C++26// constexpr since C++26
+// void push_back(value_type&& x); // constexpr since C++26
 
 #include <list>
 #include <cassert>