[m-rev.] for review: implement --warn-stdlib-shadowing, part 2

[Zoltan Somogyi]

On Fri, 7 Jan 2022 22:58:58 +1100 (AEDT), Julien Fischer <jfischer at opturion.com> wrote:
> s/un documented/undocumented/

Done.

> What's the subtime module testing for?

The error message for module names that contain a stdlib
module name, but are not identical to it. I added this info
to the log message.

> The diff is fine otherwise.

Thank you.

Zoltan.