Inconsistent narrowing for `builtins.type` and `typing.Type`

The following difference is due to Mypy handling typing.Type via TypeType, for which it does not try to create an intersection, and builtins.type as an Instance, for which it does:

# flags: --python-version 3.9 --warn-unreachable

from typing import Type

t1: Type
t2: type
class C: ...

if isinstance(t1, C):
    reveal_type(t1)  # E: Statement is unreachable
if isinstance(t2, C):
    reveal_type(t2)  # N: Revealed type is "__main__.<subclass of "type" and "C">"

I encountered this problem when working on #16330, which affects type checking a sphinx function.

Interestingly, things are consistent when annotating explicitly with Any:

# flags: --python-version 3.9 --warn-unreachable

from typing import Any, Type

t1: Type[Any]
t2: type[Any]
class C: ...

if isinstance(t1, C):
    reveal_type(t1)  # E: Statement is unreachable
if isinstance(t2, C):
    reveal_type(t2)  # E: Statement is unreachable

So, Mypy maybe misunderstands t2: type?

Start with the reproducer in the issue using the stated Python 3.9 and --warn-unreachable settings. Trace how Mypy narrows typing.Type through TypeType versus builtins.type through Instance, then compare the behavior with the explicit Any examples. Done means the inconsistent narrowing is resolved and the shown cases produce consistent diagnostics and revealed types.