P3697R1: Minor additions to C++26 standard library hardening

[frederick-vs-ja]

Link: https://wg21.link/P3697R1

Feature-test macros:

#define __cpp_lib_hardened_basic_stacktrace       202506L // also in <stacktrace>
#define __cpp_lib_hardened_common_iterator        202506L // also in <iterator>
#define __cpp_lib_hardened_counted_iterator       202506L // also in <iterator>
#define __cpp_lib_hardened_shared_ptr_array       202506L // also in <memory>
#define __cpp_lib_hardened_view_interface         202506L // also in <ranges>