[Bug libstdc++/93469] memory header fails to compile with _XOPEN_SOURCE macro defined and -std=c++2a option specified

[karen.arutyunov at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93469

--- Comment #4 from Karen <karen.arutyunov at gmail dot com> ---
Here the additional info:

GCC version: Apple clang version 11.0.0 (clang-1100.0.33.16)
Target: x86_64-apple-darwin19.2.0
Configured with: --prefix=/Library/Developer/CommandLineTools/usr
--with-gxx-include-dir=/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/c++/4.2.1