...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: If3430e23fff7bb0da12ae20579696869bdf9b3d8
Reviewed-on: https://gerrit.libreoffice.org/58082
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>