py/runtime: Support importing a method from an instance.

This change follows CPython behaviour, allowing use of:

    from instance import method

to import a bound method from a class instance, eg registered via
setting `sys.modules["instance"] = instance`.

Admittedly this is probably a very rarely used pattern in Python, but it
resolves a long standing comment about whether or not this is actually
possible (it turns out it is possible!).  A test is added to show how it
works.

The main reason for this change is to fix a problem with imports in the
webassembly port: prior to this fix, it was not possible to do `from
js_module import function`, where `js_module` is a JavaScript object
registered to be visible to Python through the webassembly API function
`registerJsModule(js_module)`.  But now with this fix that is possible.

Signed-off-by: Damien George <damien@micropython.org>

0 files changed, 0 insertions, 0 deletions