KT-53465, KT-53677 Get rid of unnecessary checkcasts to array of reified type

compiler/testData/codegen/box/casts/kt48927_privateMethodOnDerivedCastToBase.kt

@@ -2,8 +2,13 @@ abstract class Base {
     private fun test(): String = "OK"
 
     fun test(d: Derived): String = (d as Base).test()
+
+    fun test(d: Array<out Derived>) = (d as Array<out Base>)[0].test()
 }
 
 class Derived : Base()
 
-fun box(): String = Derived().test(Derived())
+fun box(): String {
+    Derived().test(arrayOf(Derived()))
+    return Derived().test(Derived())
+}