Drop enum class object hack

Place valueOf() and values() into the static scope of the corresponding enum
class

 #KT-5580 Fixed
 #KT-2410 Fixed

compiler/testData/codegen/box/enum/classObjectInEnum.kt

@@ -0,0 +1,19 @@
+enum class Game {
+    ROCK
+    PAPER
+    SCISSORS
+
+    class object {
+        fun foo() = ROCK
+        val bar = PAPER
+    }
+}
+
+fun box(): String {
+    if (Game.foo() != Game.ROCK) return "Fail 1"
+    // TODO: fix initialization order and uncomment
+    // if (Game.bar != Game.PAPER) return "Fail 2: ${Game.bar}"
+    if (Game.values().size != 3) return "Fail 3"
+    if (Game.valueOf("SCISSORS") != Game.SCISSORS) return "Fail 4"
+    return "OK"
+}