[FIR] Don't miss modality of anonymous objects in canHaveSubtypes()

They are not `FirRegularClassSymbol`, but are
final. `FirClassSymbol` is enough, because
`toSymbol()` returns `FirClassifierSymbol`, and:

- type parameters are always expected to have
  subtypes
- typealiases have been expanded in the
  previous line

compiler/testData/diagnostics/tests/enum/incompatibleEnumEntryClasses.fir.kt

@@ -1,92 +0,0 @@
-// !LANGUAGE: -ProhibitComparisonOfIncompatibleEnums
-
-interface I {
-    fun foo()
-}
-
-enum class E1 : I {
-    A {
-        override fun foo() {
-            <!INCOMPATIBLE_ENUM_COMPARISON!>this == E2.A<!>
-
-            val q = this
-            when (q) {
-                this -> {}
-                E1.A -> {}
-                E1.B -> {}
-                <!INCOMPATIBLE_ENUM_COMPARISON!>E2.A<!> -> {}
-                <!INCOMPATIBLE_ENUM_COMPARISON!>E2.B<!> -> {}
-                else -> {}
-            }
-        }
-    },
-    B {
-        override fun foo() {
-
-        }
-    }
-}
-
-enum class E2 : I {
-    A {
-        override fun foo() {
-
-        }
-    },
-    B {
-        override fun foo() {
-
-        }
-    }
-}
-
-fun foo1(e1: E1, e2: E2) {
-    <!INCOMPATIBLE_ENUM_COMPARISON!>e1 == e2<!>
-    <!INCOMPATIBLE_ENUM_COMPARISON!>e1 != e2<!>
-
-    <!INCOMPATIBLE_ENUM_COMPARISON!>e1 == E2.A<!>
-    <!INCOMPATIBLE_ENUM_COMPARISON!>E1.B == e2<!>
-
-    <!INCOMPATIBLE_ENUM_COMPARISON!>E1.A == E2.B<!>
-
-    e1 == E1.A
-    E1.A == e1
-    e2 == E2.B
-    E2.B == e2
-}
-
-fun foo2(e1: E1, e2: E2) {
-    when (e1) {
-        E1.A -> {}
-        <!INCOMPATIBLE_ENUM_COMPARISON!>E2.A<!> -> {}
-        <!INCOMPATIBLE_ENUM_COMPARISON!>E2.B<!> -> {}
-        e1 -> {}
-        <!INCOMPATIBLE_ENUM_COMPARISON!>e2<!> -> {}
-        else -> {}
-    }
-}
-
-fun foo3(e1: Enum<E1>, e2: Enum<E2>, e: Enum<*>) {
-    e1 == e
-    e1 == e2
-
-    e1 == E1.A
-    e1 == E2.A
-
-    when (e1) {
-        e1 -> {}
-        e2 -> {}
-        e -> {}
-        E1.A -> {}
-        E2.A -> {}
-        else -> {}
-    }
-
-    when (e) {
-        e -> {}
-        e2 -> {}
-        E1.A -> {}
-        E2.A -> {}
-        else -> {}
-    }
-}

compiler/testData/diagnostics/tests/enum/incompatibleEnumEntryClasses.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // !LANGUAGE: -ProhibitComparisonOfIncompatibleEnums
 
 interface I {