Delete kotlin.jvm.internal.KObject

It was supposed to be used in reflection but the benefits do not outweigh the
cost of KT-6951

 #KT-3223 Fixed
 #KT-6951 Fixed

compiler/testData/asJava/lightClasses/nullabilityAnnotations/IntOverridesAny.java

@@ -1,4 +1,4 @@
-public final class C implements kotlin.jvm.internal.KObject, Tr {
+public final class C implements Tr {
     private final int v = 1;
 
     @org.jetbrains.annotations.NotNull