Bound TypeVar doesn't unify with its bound

[Daenyth]

from typing import *
U = Union[int, str]
d: Dict[Type[U], int] = {int: 1, str: 2}
T = TypeVar('T', bound=U)
def get(t: Type[T]) -> int:
    return d[t]

foo.py:6: error: Invalid index type Type[T] for Dict[Union[Type[int], Type[str]], int]; expected type "Union[Type[int], Type[str]]"

Using mypy 0.521

[ilevkivskyi]

FWIW, here:

T = TypeVar('T', bound=U)
def get(t: Type[T]) -> int:
    return d[t]

type variable is not necessary (it is very rare when it makes sense to have a type variable for a single argument in function). For example this:

U = Union[int, str]
d: Dict[Type[U], int] = {int: 1, str: 2}
def get(t: Type[U]) -> int:
    return d[t]

works just fine.

[Daenyth]

In the real code I do have it used more heavily in a way that makes sense - this was just a more minimal example, though apparently I didn't reduce it all the way.

[ilevkivskyi]

This looks like a remainder of #3039, if I use T instead Type[T] plus corresponding changes elsewhere, then everything works.