look for classes which only have copy/move constructors, and so are
effectively dead

Change-Id: I0b844f301e2200c2b40031856bfdb0b0e2c8f77d
Reviewed-on: https://gerrit.libreoffice.org/41039Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>