Overeager type narrowing

I'm implementing type narrowing and thinking about intersection types for Python in general and I noticed this behavior in mypy:

Point = tuple[int, int]

class Shape: pass

def scale(x: float, o: int | Point | Shape):
  if isinstance(o, tuple):
    reveal_type(o)

Will show Tuple[builtins.int, builtins.int] which might seem reasonable but what if there's

class ColorShape(Shape, tuple[Shape, str]): pass

We should say that the intersection of Point and tuple (= tuple[Any, ...]) is Point (= tuple[int, int]). The intersection of Shape and tuple is not known to be empty.

The intersection of int and tuple is known to be empty for CPython because:

>>> class A(int, tuple): pass
... 
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: multiple bases have instance lay-out conflict

Start by running the inline mypy example and checking the revealed type for the isinstance(o, tuple) branch. Trace the type-narrowing behavior for the Point, Shape, and int union members; done means narrowing preserves possible tuple intersections without treating unrelated or potentially compatible types as impossible.