Redundant modality modifier inspection #KT-11450 Fixed

idea/testData/inspections/redundantModalityModifier/redundantModalityModifier.kt

@@ -0,0 +1,42 @@
+// Abstract
+abstract class Base {
+    // Redundant final
+    final fun foo() {}
+    // Abstract
+    abstract fun bar()
+    // Open
+    open val gav = 42
+}
+
+class FinalDerived : Base() {
+    // Redundant final
+    override final fun bar() {}
+    // Non-final member in final class
+    override open val gav = 13
+}
+// Open
+open class OpenDerived : Base() {
+    // Final
+    override final fun bar() {}
+    // Redundant open
+    override open val gav = 13
+}
+// Redundant final
+final class Final
+// Interface
+interface Interface {
+    // Redundant
+    abstract fun foo()
+    // Redundant
+    private final fun bar() {}
+    // Redundant
+    open val gav: Int
+        get() = 42
+}
+// Derived interface
+interface Derived : Interface {
+    // Redundant
+    override open fun foo() {}
+    // Redundant
+    final class Nested
+}