Summary:
This diff replaces overridden method calls in ObjC when possible, ie the first parameter of the
method has a sub-class type of the method's class. For example,
when `MyEnumerator` is a sub-class of `NSEnumerator` and there is overridden `nextObject`,
```
[my_enumerator nextObject]
```
in Sil, it was translated to like
```
NSEnumerator.nextObject(my_enumerator : MyEnumerator*)
```
and the analyzer missed the overridden method. This diff replaces the function call to
```
MyEnumerator.nextObject(my_enumerator : MyEnumerator*)
```
Reviewed By: ezgicicek
Differential Revision: D24477290
fbshipit-source-id: 6842a76f8
Sungkeun Cho