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)))
      |

Start with src/util.h around lines 506-507 and test/cctest/test_util.cc around line 229, then reproduce the warning on the reported macOS toolchain. Trace the MaybeStackBuffer instantiation and identify the supported C++ API path; done means the affected test build no longer emits these deprecation warnings.