FIR: consider enum class overridden members non-final #KT-48164 Fixed

compiler/fir/analysis-tests/testData/resolveWithStdlib/intellij/EnumWithToString.fir.txt

@@ -0,0 +1,28 @@
+FILE: EnumWithToString.kt
+    public final enum class Some : R|kotlin/Enum<Some>| {
+        private constructor(): R|Some| {
+            super<R|kotlin/Enum<Some>|>()
+        }
+
+        public final static enum entry ENTRY: R|Some| = object : R|Some| {
+            private constructor(): R|<anonymous>| {
+                super<R|Some|>()
+            }
+
+            public final override fun toString(): R|kotlin/String| {
+                ^toString String(Entry)
+            }
+
+        }
+
+        public open override fun toString(): R|kotlin/String| {
+            ^toString String(Some)
+        }
+
+        public final static fun values(): R|kotlin/Array<Some>| {
+        }
+
+        public final static fun valueOf(value: R|kotlin/String|): R|Some| {
+        }
+
+    }

compiler/fir/analysis-tests/testData/resolveWithStdlib/intellij/EnumWithToString.kt

@@ -0,0 +1,7 @@
+enum class Some {
+    ENTRY {
+        override fun toString(): String = "Entry"
+    };
+
+    override fun toString(): String = "Some"
+}

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirDiagnosticTestGenerated.java

@@ -5038,6 +5038,12 @@ public class FirDiagnosticTestGenerated extends AbstractFirDiagnosticTest {
             public void testDailyAggregatedDoubleFactor() throws Exception {
                 runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/intellij/DailyAggregatedDoubleFactor.kt");
             }
+
+            @Test
+            @TestMetadata("EnumWithToString.kt")
+            public void testEnumWithToString() throws Exception {
+                runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/intellij/EnumWithToString.kt");
+            }
         }
 
         @Nested

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirDiagnosticsWithLightTreeTestGenerated.java

@@ -5038,6 +5038,12 @@ public class FirDiagnosticsWithLightTreeTestGenerated extends AbstractFirDiagnos
             public void testDailyAggregatedDoubleFactor() throws Exception {
                 runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/intellij/DailyAggregatedDoubleFactor.kt");
             }
+
+            @Test
+            @TestMetadata("EnumWithToString.kt")
+            public void testEnumWithToString() throws Exception {
+                runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/intellij/EnumWithToString.kt");
+            }
         }
 
         @Nested

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirStatusResolver.kt

@@ -258,7 +258,13 @@ class FirStatusResolver(
                         }
                     }
                     else -> {
-                        if (declaration.isOverride && containingClass.modality != Modality.FINAL) Modality.OPEN else Modality.FINAL
+                        if (declaration.isOverride &&
+                            (containingClass.modality != Modality.FINAL || containingClass.classKind == ClassKind.ENUM_CLASS)
+                        ) {
+                            Modality.OPEN
+                        } else {
+                            Modality.FINAL
+                        }
                     }
                 }
             }

idea/idea-frontend-fir/idea-fir-low-level-api/tests/org/jetbrains/kotlin/idea/fir/low/level/api/diagnostic/compiler/based/DiagnosisCompilerFirTestdataTestGenerated.java

@@ -5038,6 +5038,12 @@ public class DiagnosisCompilerFirTestdataTestGenerated extends AbstractDiagnosis
             public void testDailyAggregatedDoubleFactor() throws Exception {
                 runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/intellij/DailyAggregatedDoubleFactor.kt");
             }
+
+            @Test
+            @TestMetadata("EnumWithToString.kt")
+            public void testEnumWithToString() throws Exception {
+                runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/intellij/EnumWithToString.kt");
+            }
         }
 
         @Nested