push back dead objects to free list
push back dead objects to free list

dcurrie/picrin,leavesbnw/picrin,ktakashi/picrin,dcurrie/picrin,omasanori/picrin,omasanori/picrin,leavesbnw/picrin,ktakashi/picrin,picrin-scheme/picrin,leavesbnw/picrin,koba-e964/picrin,koba-e964/picrin,ktakashi/picrin,picrin-scheme/picrin,koba-e964/picrin