$ffb83754 string-prototype-char-at-builtin.js:4:13
  Registers: 8
  Blocks:    1
  Constants:
    [0] = String("abc")
    [1] = Int32(1)
    [2] = String("charAt")

block0:
  [   0] GetById dst:reg6, base:String("abc"), `charAt` ('abc'.charAt)
  [  20] CallBuiltinStringPrototypeCharAt dst:reg5, callee:reg6, this_value:String("abc"), argument:Int32(1), 'abc'.charAt
  [  38] GetById dst:reg7, base:String("abc"), `charAt`
  [  58] Call dst:reg6, callee:reg7, this_value:String("abc"), 'abc'['charAt'], arguments:[Int32(1)]
  [  80] End value:reg6