reveal_type should indicate untyped defs with types

[graingert]

Feature

It's possible to make a def that's simultaneously typed and untyped eg: https://mypy-play.net/?mypy=latest&python=3.9&flags=disallow-untyped-calls&gist=7946ef5bbce794503defa44284147e56

Here Lock is "untyped" but appears to be a main.py:17: note: Revealed type is 'def () -> main.Lock'

Pitch
reveal_type should let me know that this object has an untyped constructor:

main.py:17: note: Revealed type is 'Untyped[def () -> main.Lock']

See also #5943 (comment)

this tripped up the anyio project in the definition of anyio.Lock agronholm/anyio#289

[adamchainz]

The first error message could be main.py:11: error: Call to untyped function "Lock.__init__" in typed context - since it's the initializer not the constructor that's the problem. Presumably it's also possible to have a typed __new__ but untyped __init__?

reveal_type(Lock.__init__) says main.py:17: note: Revealed type is 'def (self: main.Lock) -> Any'