Further investigate handling of type aliases by locality and uniqueness checkers

Consider the following test:

```kotlin
class A

typealias B = A

fun share(x: B) {}

fun test(x: @Borrowed A) { share(x) }
```

In this case the locality checker correctly detects the locality mismatch in `test`. Make sure that there aren't any corner cases that we may be missing in relation to type aliases.