anchor.diff:  (test-js-eval loop-parallel-clauses-with-return
      (loop :for i :from 0 :below 10 :for x = (* i 10)
        :when (> i 5) :do (return x)
  -     :collect i)
  +     :collecting i)
      60)
   
   (test-js-eval loop-extended-conditional-clauses
  
positive.code:     bar)
    '(1 2 2 1 3 4 4 2 5 6 6 3 21))
  
  (test-js-eval loop-conditional-return-works
    (block nil
      (dotimes (i 10)
  
negative.code: (test-js-eval for-obj-place-in
    (loop :for (:a :b) :in (list (create :a 2 :b 3)
                                 (create :a 4 :b 5))
      :summing (+ a b))
    14)
  
  (test-js-eval for-arr-place-=
  