SERVER-8514 $in count query with null array yields error on empty collection when $in syntax invalid

query canonicalization is perfromed before executor would return if no collection exists. So if we call invalid query on non-existing collection status of invalid query will return before it reports 0 records on non-existing collection
For completeness, you might want to add cases for:

- empty collection
- find(q).itcount() - this returns an iterator from the server and the count is done on the client side.