inspection and code cleanup for redundant visibility modifiers

idea/testData/inspections/redundantVisibilityModifier/redundantVisibilityModifier.kt

@@ -0,0 +1,22 @@
+public class C {
+    public val foo: Int = 0
+
+    public fun bar() {}
+
+}
+
+open class D {
+    protected open fun willRemainProtected() {
+    }
+
+    protected open fun willBecomePublic() {
+    }
+}
+
+class E : D() {
+    protected override fun willRemainProtected() {
+    }
+
+    public override fun willBecomePublic() {
+    }
+}