...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: Iacfdd89ca6ca3af19a56cd26721e1ce2d47c49fa
Reviewed-on: https://gerrit.libreoffice.org/58055
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>