Add data modifier to a class quickfix #KT-18220 Fixed

idea/testData/quickfix/addDataModifier/test6.kt

@@ -0,0 +1,8 @@
+// "Make 'Foo' data class" "true"
+class Foo(private val bar: String, protected var baz: Int) {
+    class A {
+        fun test() {
+            var (bar, baz) = Foo("A", 1)<caret>
+        }
+    }
+}