$546ebce0 annexb-var-coordinate-with-default-param.js:12:1
  Registers: 7
  Blocks:    1
  Constants:
    [0] = Undefined

block0:
  [   0] GetGlobal dst:reg6, `f`
  [  10] Call dst:reg5, callee:reg6, this_value:Undefined, f
  [  30] End value:reg5


f$40af7db5 annexb-var-coordinate-with-default-param.js:4:5
  Registers: 10
  Blocks:    3
  Constants:
    [0] = Int32(1)
    [1] = Undefined
    [2] = Int32(2)
    [3] = Bool(true)

block0:
  [   0] GetLexicalEnvironment dst:reg4
  [   8] CreateLexicalEnvironment dst:reg5, parent:reg4, capacity:0, is_catch_environment:false
  [  20] CreateVariable `x`, is_immutable:false, is_global:false, is_strict:false
  [  30] JumpUndefined condition:arg0, true_target:block1, false_target:block2

block1:
  [  40] Mov dst:arg0, src:Int32(1)

block2:
  [  50] InitializeLexicalBinding `x`, src:arg0
  [  68] CreateVariable `g`, is_immutable:false, is_global:false, is_strict:false
  [  78] InitializeVariableBinding `g`, src:Undefined
  [  90] CreateLexicalEnvironment dst:reg6, parent:reg5, capacity:1, is_catch_environment:false
  [  a8] CreateVariable `y`, is_immutable:false, is_global:false, is_strict:false
  [  b8] InitializeLexicalBinding `y`, src:Int32(2)
  [  d0] CreateLexicalEnvironment dst:reg7, parent:reg6, capacity:0, is_catch_environment:false
  [  e8] CreateMutableBinding environment:reg7, `g`, can_be_deleted:false
  [  f8] NewFunction dst:reg8, shared_function_data_index:0
  [ 110] InitializeLexicalBinding `g`, src:reg8
  [ 128] GetBinding dst:reg8, `g`
  [ 140] SetVariableBinding `g`, src:reg8
  [ 158] SetLexicalEnvironment environment:reg6
  [ 160] GetCalleeAndThisFromEnvironment callee:reg8, this_value:reg9, `g`
  [ 178] Call dst:reg7, callee:reg8, this_value:reg9, g
  [ 198] Return value:reg7


g$b7262970 annexb-var-coordinate-with-default-param.js:7:13
  Registers: 8
  Blocks:    1

block0:
  [   0] DynamicGetBinding dst:reg5, `x`
  [  10] DynamicGetBinding dst:reg6, `y`
  [  20] Add dst:reg7, lhs:reg5, rhs:reg6
  [  30] Return value:reg7