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.
This fixes a bunch of missing overridden symbols in IR.
This is also required for fixing KT-59921 in the following commit
where we need to keep all overridden symbols of intersection overrides
so that we can enhance them properly.
#KT-57300 Fixed
#KT-57299 Fixed
#KT-59921
#KT-57300
#KT-62788
#KT-64271
#KT-64382
This big refactoring is needed to cleanup building of overrides
mappings and prevent creating redundant intersection overrides in
cases when there is no need in them:
```kotlin
interface A {
fun foo()
}
interface B {
fun foo()
}
interface C : A, B {
override fun foo()
}
```
Before this refactoring there was next override tree:
C.foo
intersection override (A.foo, B.foo)
A.foo
B.foo
Also this commit fixes special mapping of overrides in jvm scopes
for declarations which have kotlin builtins in supertypes with
special java mapping rules (collections, for example)