K2: use ClassKind.CLASS for object literals

K1 uses CLASS, and libraries like kotlinx-metadata-jvm and
kotlin-reflect already rely on it.

 #KT-57641 Fixed

libraries/tools/kotlinp/testData/localClasses/AnonymousObject.kt

@@ -1,5 +1,3 @@
-// IGNORE K2
-
 fun test() = object : Runnable {
     override fun run() { }
 }