...by removing explicitly user-provided functions that do the same as their
implicitly-defined counterparts, but may prevent implicitly declared copy
functions from being defined as non-deleted in the future

Change-Id: I75e356ee9e12bb2d88ed9db6c60c49b3f4ac5d58
Reviewed-on: https://gerrit.libreoffice.org/58056
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>