I noticed the following cases stopped working after commit a036543.

;; should not fail
(cl-loop for i from 1 upto 100 and j = 1 then (1+ j)
         do (cl-assert (= i j) t)
         until (> j 10))

;; should return (1 0)
(cl-loop with result
         for x below 3
         for y below 2
         and z = (progn (push x result) nil)
         finally return result)