Goto Definition does not work with class methods when modules reference each other

Works in a single file, but not cross-files, specifically with circular references. Works if method is not a class method.

`module1`:
```python
from .module2 import Derived1

class Base(object):
 @classmethod
 def fob_base(cls): 
 pass

class Derived2(Derived1):
 pass

Derived2.fob_base()
```
`module2`:
```python
from module1 import *

class Derived1(Base):
 pass
```