vlib/v/checker/tests/redefining_builtin_pub_functions.vv:1:1: error: cannot redefine builtin public function `exit`
    1 | fn exit(x string) {
      | ~~~~~~~~~~~~~~~~~
    2 |     println('my exit: $x')
    3 | }
vlib/v/checker/tests/redefining_builtin_pub_functions.vv:5:1: error: cannot redefine builtin public function `print_backtrace`
    3 | }
    4 | 
    5 | fn print_backtrace() {
      | ~~~~~~~~~~~~~~~~~~~~
    6 |     println('hello')
    7 | }