Feature: show failure step when compilation failed due to static analysis

Newcomers might find this kind of output useful for an invalid program:
```
✓ Syntax valid!
✗ Types invalid
- Borrow checker

error[E0599]: no method named `collect` found for type `std::vec::Vec<T>` in the current scope
...
```

This would make it easier to see if you're fixing errors correctly, and are getting 'better' errors.