rewrite arithmetic operators and comparators with pic_op
rewrite arithmetic operators and comparators with pic_op

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