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

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

@@ -0,0 +1,45 @@
+// WITH_RUNTIME
+
+package foo
+
+import kotlin.test.assertEquals
+
+enum class TestA {
+    FIRST {
+        override val label: String = "first A"
+    },
+    SECOND {
+        override val label: String = "second A"
+    },
+    THIRD {
+        override val label: String = "third A"
+    };
+
+    abstract val label: String
+}
+
+enum class TestB(val label: String) {
+    FIRST("first B"),
+    SECOND("second B"),
+    THIRD("third B");
+}
+
+fun box(): String {
+    assertEquals(TestA.FIRST.label, "first A")
+    assertEquals(TestA.SECOND.label, "second A")
+    assertEquals(TestA.THIRD.label, "third A")
+
+    assertEquals(TestA.FIRST.ordinal, 0)
+    assertEquals(TestA.SECOND.ordinal, 1)
+    assertEquals(TestA.THIRD.ordinal, 2)
+
+    assertEquals(TestB.FIRST.label,"first B")
+    assertEquals(TestB.SECOND.label,"second B")
+    assertEquals(TestB.THIRD.label,"third B")
+
+    assertEquals(TestB.FIRST.ordinal, 0)
+    assertEquals(TestB.SECOND.ordinal, 1)
+    assertEquals(TestB.THIRD.ordinal, 2)
+
+    return "OK"
+}