static mut should not be used

[programmerjake]

See #683 (comment)

[programmerjake]

Yeah, but this is not a new part that this PR introduced.
It is copy-pasted from type_object.rs.

Though I completely agree that it is problematic, maybe what I need is a mechanism that inhibits access to uninitialized TYPE_OBJECT.
Let's do it in another PR.

what about using once_cell::Lazy (or similar)?

[kngwyu]

what about using once_cell::Lazy (or similar)?

It is a possible candidate, but the first choice we have to do is probably we should make this thread_local or not.

[programmerjake]

what about using once_cell::Lazy (or similar)?

It is a possible candidate, but the first choice we have to do is probably we should make this thread_local or not.

I'm pretty sure that the returned pointer is used directly by CPython and is relied on to be unique program-wide, therefore thread_local can't be used due to it having a different address in each thread.