- encapsulate semantic more into helpers
- allow lazy scopes iteration
- simplify reporting code in tower resolver
- fix some inconsistencies and wrong lookups
- remove redundant lookup recordings
- remove lookup scopes for non-star imports
The commit is a refactoring and doesn't change the behaviour of
neither IC nor CRI. Changes in the lookups are mostly due to the
previous obviously wrong lookups (see changed test data).
Ilya Chernikov