maintainer-feedback requested: [Bug 265962] lang/gcc11: expose non-default -stdlib=libc++ support

Bugzilla Automation <bugzilla@FreeBSD.org> has asked freebsd-toolchain (Nobody)
<toolchain@FreeBSD.org> for maintainer-feedback:
Bug 265962: lang/gcc11: expose non-default -stdlib=libc++ support
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=265962



--- Description ---
$ pkg install gcc11
$ echo 'int main() {}' >a.cc
$ gcc11 -stdlib=libc++ a.cc
gcc11: error: unrecognized command-line option '-stdlib=libc++'

$ man gcc11 | col -b | fgrep -A9 stdlib=
       -stdlib=libstdc++,libc++
	   When G++ is configured to support this option, it allows
	   specification of alternate C++ runtime libraries.  Two options are
	   available: libstdc++ (the default, native C++ runtime for G++) and
	   libc++ which is the C++ runtime installed on some operating systems
	   (e.g. Darwin versions from Darwin11 onwards).  The option switches
	   G++ to use the headers from the specified library and to emit
	   "-lstdc++" or "-lc++" respectively, when a C++ runtime is required
	   for linking.