[libc++] <experimental/simd> Fix vector_aligned_tag (#76611)

Co-authored-by: Nikolas Klauser <[email protected]>

Author: joy2myself

libcxx/include/experimental/__simd/aligned_tag.h

@@ -11,6 +11,7 @@
 #define _LIBCPP_EXPERIMENTAL___SIMD_ALIGNED_TAG_H
 
 #include <__memory/assume_aligned.h>
+#include <__type_traits/remove_const.h>
 #include <cstddef>
 #include <experimental/__config>
 #include <experimental/__simd/traits.h>
@@ -35,7 +36,7 @@ inline constexpr bool is_simd_flag_type_v<element_aligned_tag> = true;
 
 struct vector_aligned_tag {
   template <class _Tp, class _Up = typename _Tp::value_type>
-  static constexpr size_t __alignment = memory_alignment_v<_Tp, _Up>;
+  static constexpr size_t __alignment = memory_alignment_v<_Tp, remove_const_t<_Up>>;
 
   template <class _Tp, class _Up>
   static _LIBCPP_HIDE_FROM_ABI constexpr _Up* __apply(_Up* __ptr) {