GH-42536: [C++] Replace std::aligned_storage that is deprecated in C++23

Fixes #41536

Author: sjoubert

cpp/cmake_modules/SetupCxxFlags.cmake

@@ -163,21 +163,6 @@ if(WIN32)
   # insecure, like std::getenv
   add_definitions(-D_CRT_SECURE_NO_WARNINGS)
 
-  # Disable static assertion in Microsoft C++ standard library.
-  #
-  # """[...]\include\type_traits(1271): error C2338:
-  # You've instantiated std::aligned_storage<Len, Align> with an extended
-  # alignment (in other words, Align > alignof(max_align_t)).
-  # Before VS 2017 15.8, the member type would non-conformingly have an
-  # alignment of only alignof(max_align_t). VS 2017 15.8 was fixed to handle
-  # this correctly, but the fix inherently changes layout and breaks binary
-  # compatibility (*only* for uses of aligned_storage with extended alignments).
-  # Please define either (1) _ENABLE_EXTENDED_ALIGNED_STORAGE to acknowledge
-  # that you understand this message and that you actually want a type with
-  # an extended alignment, or (2) _DISABLE_EXTENDED_ALIGNED_STORAGE to silence
-  # this message and get the old non-conformant behavior."""
-  add_definitions(-D_ENABLE_EXTENDED_ALIGNED_STORAGE)
-
   if(MSVC)
     # ARROW-1931 See https://github.com/google/googletest/issues/1318
     #

cpp/src/arrow/util/aligned_storage.h

@@ -119,26 +119,7 @@ class AlignedStorage {
   }
 
  private:
-#if !defined(__clang__) && defined(__GNUC__) && defined(__i386__)
-  // Workaround for GCC bug on i386:
-  //   alignof(int64 | float64) can give different results depending on the
-  //   compilation context, leading to internal ABI mismatch manifesting
-  //   in incorrect propagation of Result<int64 | float64> between
-  //   compilation units.
-  // (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88115)
-  static constexpr size_t alignment() {
-    if (std::is_integral_v<T> && sizeof(T) == 8) {
-      return 4;
-    } else if (std::is_floating_point_v<T> && sizeof(T) == 8) {
-      return 4;
-    }
-    return alignof(T);
-  }
-
-  typename std::aligned_storage<sizeof(T), alignment()>::type data_;
-#else
-  typename std::aligned_storage<sizeof(T), alignof(T)>::type data_;
-#endif
+  alignas(T) std::byte data_[sizeof(T)];
 };
 
 }  // namespace internal