The reason #1 for this feature is that we want to test IdSignatures
generated for declarations. Currently, there is no (easy) way to ensure
that a change in the signature building logic doesn't cause any breaking
changes wrt klibs.
Now, most IdSignatures include hashed mangled names in them, so even if
we catch a regression where the included hash changes, there would be no
way of knowing immediately what caused it, unless we'd also have mangled
names in the expectations.
The reason #2 is to test the manglers themselves. Currently, there are
no tests for them. They heavily duplicate each other, this is already
causing issues (see KT-57427) that would be very hard to catch without
these tests.
^KT-58238 Fixed
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)
Sergej Jaskiewicz