Complex enum entries (those with bodies) with missing overrides
are covered by an existing checker that checks all types of classes. But
simple enum entries (those without bodies) were not covered and require
a separate checker for missing overrides.
#KT-58637 Fixed
Previously `FirPropertyAccessor.source` references the `KtProperty` if
the user code contains a setter or getter that doesn't contain a body.
For example, with the following
```
val i: Int = 1
private set
```
The `FirPropertyAccessor` would reference the `KtProperty` as the
source.
This change makes `FirPropertyAccessor` reference `KtPropertyAccessor`
as the source if possible, regardless of whether the body is present or
not.
Brian Norman