[FIR] Allow declarations to override parts of non-trivial intersection

A class can inherit two declarations that are compatible from the
overridability standpoint and are therefore combined to a non-trivial
intersection.
At the same time, the class can declare a member declaration that
only overrides one of the intersection's members.
In this case, we break up the intersection and only add the overridden
parts to the declared member's direct overridden list.

If the class doesn't override the intersection, it exists as
intersection override, like before.

#KT-65487 Fixed

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/scopes/JavaClassUseSiteMemberScope.kt

@@ -32,6 +32,7 @@ import org.jetbrains.kotlin.fir.scopes.*
 import org.jetbrains.kotlin.fir.scopes.impl.AbstractFirUseSiteMemberScope
 import org.jetbrains.kotlin.fir.scopes.impl.FirTypeIntersectionScopeContext.ResultOfIntersection
 import org.jetbrains.kotlin.fir.scopes.impl.MembersByScope
+import org.jetbrains.kotlin.fir.scopes.impl.isIntersectionOverride
 import org.jetbrains.kotlin.fir.scopes.impl.similarFunctionsOrBothProperties
 import org.jetbrains.kotlin.fir.scopes.jvm.computeJvmDescriptor
 import org.jetbrains.kotlin.fir.symbols.impl.*
@@ -400,6 +401,20 @@ class JavaClassUseSiteMemberScope(
         return result.toSet()
     }
 
+    private fun <D : FirCallableSymbol<*>> ResultOfIntersection<D>.extractSomeSymbolFromSuperType(): D {
+        return if (this.isIntersectionOverride()) {
+            /*
+             * we don't want to create intersection override if some declared function actually overrides some functions
+             *   from supertypes, so instead of intersection override symbol we check actual symbol from supertype
+             *
+             * TODO(KT-65925): is it enough to check only one function?
+             */
+            keySymbol
+        } else {
+            chosenSymbol
+        }
+    }
+
     private fun processSpecialFunctions(
         requestedName: Name,
         explicitlyDeclaredFunctionsWithNaturalName: Collection<FirNamedFunctionSymbol>,