...when instantiating implicitly defined special member functions of
SVX_DLLPUBLIC EnhancedCustomShape2d, due to seqSubViewSize member

Change-Id: I7dd22ba0602461c1bbe2e1e5351e161f2e098c37
Reviewed-on: https://gerrit.libreoffice.org/73404
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>