$916dd419 for-in-block-order.js:5:1
  Registers: 8
  Blocks:    1
  Constants:
    [0] = Undefined

block0:
  [   0] GetGlobal dst:reg6, `foo`
  [  18] NewObject dst:reg7
  [  28] Call dst:reg5, callee:reg6, this_value:Undefined, foo, arguments:[reg7]
  [  50] End value:reg5


foo$3b347bf9 for-in-block-order.js:2:16
  Registers: 8
  Blocks:    6
  Locals:    k~0
  Constants:
    [0] = Undefined

block0:
  [   0] Mov dst:k~0, src:Undefined
  [  10] JumpNullish condition:arg0, true_target:block3, false_target:block4

block1:
  [  20] End value:Undefined

block2:
  [  28] ObjectPropertyIteratorNext dst_value:reg6, dst_done:reg7, iterator_object:reg5
  [  38] JumpIf condition:reg7, true_target:block1, false_target:block5

block3:
  [  48] Jump target:block1

block4:
  [  50] GetObjectPropertyIterator dst_iterator:reg5, object:arg0
  [  68] Jump target:block2

block5:
  [  70] Mov dst:k~0, src:reg6
  [  80] Jump target:block2