$ee43eb0f for-in-register-lifetime.js:1:1
  Registers: 14
  Blocks:    6
  Constants:
    [0] = String("")
    [1] = Int32(1)
    [2] = Int32(2)
    [3] = Int32(3)
    [4] = Undefined

block0:
  [   0] SetGlobal `result`, src:String("")
  [  18] NewObject dst:reg5
  [  28] InitObjectLiteralProperty object:reg5, `a`, src:Int32(1), shape_cache_index:0, property_slot:0
  [  40] InitObjectLiteralProperty object:reg5, `b`, src:Int32(2), shape_cache_index:0, property_slot:1
  [  58] InitObjectLiteralProperty object:reg5, `c`, src:Int32(3), shape_cache_index:0, property_slot:2
  [  70] CacheObjectShape object:reg5
  [  80] SetGlobal `obj`, src:reg5
  [  98] GetGlobal dst:reg5, `obj`
  [  b0] JumpNullish condition:reg5, true_target:block3, false_target:block4

block1:
  [  c0] End value:reg5

block2:
  [  c8] ObjectPropertyIteratorNext dst_value:reg7, dst_done:reg8, iterator_object:reg6
  [  d8] JumpIf condition:reg8, true_target:block1, false_target:block5

block3:
  [  e8] End value:reg5

block4:
  [  f0] GetObjectPropertyIterator dst_iterator:reg6, object:reg5
  [ 108] Mov dst:reg5, src:Undefined
  [ 118] Jump target:block2

block5:
  [ 120] SetGlobal `k`, src:reg7
  [ 138] GetGlobal dst:reg9, `result`
  [ 150] GetGlobal dst:reg10, `k`
  [ 168] GetGlobal dst:reg11, `obj`
  [ 180] GetGlobal dst:reg12, `k`
  [ 198] GetByValue dst:reg13, base:reg11, property:reg12 (obj[reg12])
  [ 1b0] Add dst:reg11, lhs:reg10, rhs:reg13
  [ 1c0] Add dst:reg10, lhs:reg9, rhs:reg11
  [ 1d0] SetGlobal `result`, src:reg10
  [ 1e8] Mov dst:reg5, src:reg10
  [ 1f8] Jump target:block2