Add test for Shrinkable move constructor
Add test for Shrinkable move constructor

tm604/rapidcheck,unapiedra/rapidfuzz,whoshuu/rapidcheck,tm604/rapidcheck,emil-e/rapidcheck,tm604/rapidcheck,emil-e/rapidcheck,emil-e/rapidcheck,unapiedra/rapidfuzz,unapiedra/rapidfuzz,whoshuu/rapidcheck,whoshuu/rapidcheck