KT-6632 "Convert to extension" intention should not be available on methods that override or implement a superclass method

#KT-6632 Fixed

idea/src/org/jetbrains/kotlin/idea/intentions/declarations/ConvertMemberToExtension.kt

@@ -36,6 +36,7 @@ public class ConvertMemberToExtension : JetSelfTargetingRangeIntention<JetCallab
         val classBody = element.getParent() as? JetClassBody ?: return null
         if (classBody.getParent() !is JetClass) return null
         if (element.getReceiverTypeReference() != null) return null
+        if (element.hasModifier(JetTokens.OVERRIDE_KEYWORD)) return null
         when (element) {
             is JetProperty -> if (element.hasInitializer()) return null
             is JetSecondaryConstructor -> return null

idea/testData/intentions/declarations/convertMemberToExtension/override.kt

@@ -0,0 +1,9 @@
+// IS_APPLICABLE: false
+trait I {
+    fun foo()
+}
+
+class C : I {
+    override fun <caret>foo() {
+    }
+}

idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java

@@ -3921,6 +3921,12 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("override.kt")
+            public void testOverride() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("idea/testData/intentions/declarations/convertMemberToExtension/override.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("private.kt")
             public void testPrivate() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("idea/testData/intentions/declarations/convertMemberToExtension/private.kt");