fix(KT-45056, KT-47516): use enum as an IR class instead of enum entity class.

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

@@ -0,0 +1,13 @@
+package foo
+
+enum class X {
+    B {
+        override val value2 = "K"
+        override val value = "O" + B.value2.get(X.B.ordinal).toString()
+    };
+
+    abstract val value2: String
+    abstract val value: String
+}
+
+fun box() = X.B.value