...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: I2b7b6b8baa872addfb2adb0d551d78de1e31c896
Reviewed-on: https://gerrit.libreoffice.org/58106
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>