Even though SO may not be correct
overrides sometimes, it feels more
natural to treat fake overrides as...
well, "overrides". And without it
we'd need to make the code in
`FirOverrideChecker` less intuitive.
NB: in order to produce correct IR origins, the source element kinds for
some FIR elements has been changed. As a side effect, mapping PSI to FIR
slightly changed: namely, for `a[b]++`, `a[b]` used to be mapped on
`set` call or callable reference, but now it is mapped on `get` call.
^KT-61891: Fixed
^KT-64387: Fixed
Instead of relying on UNRESOLVED_REFERENCE directive for the whole file,
just render the unresolved reference right in the .txt testdata
This will allow to introduce multi-caret resolve testdata more naturally
Required for KT-65152 and KT-62695
k1 would suggest `get` as well
but with current fir structure with fake desugaring
get is moved to the separate fake psi which doesn't exist
thus the problem is ignored for now
^ KTIJ-24025
Use-site substitution override happens in situations like this:
```
interface List<A> { fun get(i: Int): A }
fun take(list: List<String>) {
list.get(10) // this call
}
```
We want to have those overrides unwrapped, because we don't want
to deal with a different KtSymbol for each possible use-site
^KT-50862 Fixed
Nikolay Lunyak