Ok.

In debian il pacchetto si chiama semplicemente libstdc++5 e fornisce questi file:

/usr
/usr/share
/usr/share/doc
/usr/share/doc/libstdc++5
/usr/share/doc/libstdc++5/copyright
/usr/share/doc/libstdc++5/README.Debian
/usr/share/doc/libstdc++5/changelog.Debian.gz
/usr/lib
/usr/lib/libstdc++.so.5.0.7
/usr/lib/libstdc++.so.5