Use of deprecated C++ API in src

In file included from ../../test/cctest/test_util.cc:1:
In file included from ../../src/debug_utils-inl.h:6:
In file included from ../../src/debug_utils.h:6:
In file included from ../../src/async_wrap.h:27:
In file included from ../../src/base_object.h:29:
In file included from ../../src/memory_tracker.h:5:
In file included from ../../deps/v8/include/v8-profiler.h:10:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/memory:950:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__memory/inout_ptr.h:16:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__memory/shared_ptr.h:22:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__fwd/ostream.h:13:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__fwd/string.h:45:41: warning: 'char_traits<unsigned char>' is deprecated: char_traits<T> for T not equ
al to char, wchar_t, char8_t, char16_t or char32_t is non-standard and is provided for a temporary period. It will be removed in a future release, so please migrate off of it. [-Wdeprecated-declarations]
   45 | template <class _CharT, class _Traits = char_traits<_CharT>, class _Allocator = allocator<_CharT> >
      |                                         ^
../../src/util.h:506:15: note: in instantiation of default argument for 'basic_string<unsigned char>' required here
  506 |   inline std::basic_string<T> ToString() const { return {out(), length()}; }
      |               ^~~~~~~~~~~~~~~
../../test/cctest/test_util.cc:229:37: note: in instantiation of template class 'node::MaybeStackBuffer<unsigned char>' requested here
  229 |     MaybeStackBuffer<unsigned char> buf(100);
      |                                     ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__fwd/string.h:24:8: note: 'char_traits<unsigned char>' has been explicitly marked deprecated here
   24 | struct _LIBCPP_DEPRECATED_(
      |        ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__config:555:53: note: expanded from macro '_LIBCPP_DEPRECATED_'
  555 | #      define _LIBCPP_DEPRECATED_(m) __attribute__((__deprecated__(m)))
      |                                                     ^
In file included from ../../test/cctest/test_util.cc:1:
In file included from ../../src/debug_utils-inl.h:6:
In file included from ../../src/debug_utils.h:6:
In file included from ../../src/async_wrap.h:27:
In file included from ../../src/base_object.h:29:
In file included from ../../src/memory_tracker.h:5:
In file included from ../../deps/v8/include/v8-profiler.h:11:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/unordered_set:1846:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/functional:601:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/vector:363:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/locale:197:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__locale:28:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/string:654:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/string_view:221:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__fwd/string_view.h:22:41: warning: 'char_traits<unsigned char>' is deprecated: char_traits<T> for T no
t equal to char, wchar_t, char8_t, char16_t or char32_t is non-standard and is provided for a temporary period. It will be removed in a future release, so please migrate off of it. [-Wdeprecated-declarations]
   22 | template <class _CharT, class _Traits = char_traits<_CharT> >
      |                                         ^
../../src/util.h:507:15: note: in instantiation of default argument for 'basic_string_view<unsigned char>' required here
  507 |   inline std::basic_string_view<T> ToStringView() const {
      |               ^~~~~~~~~~~~~~~~~~~~
../../test/cctest/test_util.cc:229:37: note: in instantiation of template class 'node::MaybeStackBuffer<unsigned char>' requested here
  229 |     MaybeStackBuffer<unsigned char> buf(100);
      |                                     ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__fwd/string.h:24:8: note: 'char_traits<unsigned char>' has been explicitly marked deprecated here
   24 | struct _LIBCPP_DEPRECATED_(
      |        ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/__config:555:53: note: expanded from macro '_LIBCPP_DEPRECATED_'
  555 | #      define _LIBCPP_DEPRECATED_(m) __attribute__((__deprecated__(m)))
      |

src/util.h の 506～507 行付近と test/cctest/test_util.cc の 229 行付近から始め、報告された macOS ツールチェーンで警告を再現します。MaybeStackBuffer のインスタンス化を追跡し、サポートされている C++ API パスを特定します。対象のテストビルドでこれらの非推奨警告が出なくなれば完了です。