[jit] Calling torch.jit.script on @staticmethods which in turn call other @staticmethods results in a TypeError

[SamPruden]

🐛 Bug

Calling torch.jit.script on @staticmethods that in turn call other @staticmethods results in an internal error.

To Reproduce

class Foo:
  @staticmethod
  def bar():
    return Foo.whiz()

  @staticmethod
  def whiz():
    return 1

torch.jit.script(Foo.bar)

Results in TypeError: <module '__main__'> is a built-in class.

Environment

Google Colab with a fresh GPU runtime on which !pip install -q torch==1.4.0 has been run.

This is a spin off of #32300 at @driazati's request.

cc @suo

[suo]

Assigning to @driazati