[PATCH 1 of 2 v2] py3: handle meta-path finders that only use pre-python3.4 API

[Yuya Nishihara]

On Tue, 23 Apr 2019 23:37:17 -0400, Ludovic Chabant wrote:
> > Does find_module() return a spec? We might instead have to skip py3.4
> > finders.
> 
> Ah you're right, it returns something else. It looks like Python
> does this:
> 
>     try:
>         find_spec = finder.find_spec
>     except AttributeError:
>         loader = finder.find_module(name)
>         if loader is None:
>             return None
>         return importlib.util.spec_from_loader(name, loader)
>     else:
>         return find_spec(name)
> 
> We can either emulate the same logic, or just skip old finders?

No idea. Do we have to support unknown finders?