Default values treated differently than native runtime

[jchavarri]

Given some atd file in a module Answer:

type value = [
  | True
  | False
] <ocaml repr="classic">

type t = {
  ~mode <ocaml default="False"> : value;
}

when calling from native:

utop # Answer_j.string_of_t {mode = False};;
- : string = "{}"

but from JavaScript:

$ Answer_bs.write_t({mode: False})->Js.Json.stringify
{"mode":"False"}

The expected result should be same as native:

$ Answer_bs.write_t({mode: False})->Js.Json.stringify
{}