ExprForLoop(ref pat, ref head, ref blk, _) => {
let ln = self.propagate_through_loop(expr, ForLoop(&**pat), &**blk, succ);
self.propagate_through_expr(&**head, ln)
ExprForLoop(ref pat, ref head, ref blk, _) => {
let ln = self.propagate_through_loop(expr, ForLoop(&**pat), &**blk, succ);
self.propagate_through_expr(&**head, ln)