Resolves: fdo#71307 out polygons are limited to 16bit point count

Change-Id: I4dbe9145466d6d93ebd3dea7f4fe434c9ee3de19
(cherry picked from commit cdd351b1487a8a97f481a9165d9cd361aaee2ca4)
Reviewed-on: https://gerrit.libreoffice.org/6655
Reviewed-by: David Tardon <dtardon@redhat.com>
Tested-by: David Tardon <dtardon@redhat.com>