Added quickfix for NESTED_CLASS_NOT_ALLOWED

idea/src/org/jetbrains/jet/plugin/quickfix/QuickFixes.java

@@ -200,6 +200,8 @@ public class QuickFixes {
         factories.put(OPEN_MODIFIER_IN_ENUM, RemoveModifierFix.createRemoveModifierFromListOwnerFactory(OPEN_KEYWORD));
         factories.put(ILLEGAL_ENUM_ANNOTATION, RemoveModifierFix.createRemoveModifierFromListOwnerFactory(ENUM_KEYWORD));
 
+        factories.put(NESTED_CLASS_NOT_ALLOWED, AddModifierFix.createFactory(INNER_KEYWORD));
+
         factories.put(NOT_AN_ANNOTATION_CLASS, MakeClassAnAnnotationClassFix.createFactory());
 
         factories.put(DANGLING_FUNCTION_LITERAL_ARGUMENT_SUSPECTED, AddSemicolonAfterFunctionCallFix.createFactory());

idea/testData/quickfix/modifiers/afterNestedClassNotAllowed.kt

@@ -0,0 +1,7 @@
+// "Add 'inner' modifier" "true"
+class A() {
+    inner class B() {
+        inner class <caret>C() {
+        }
+    }
+}

idea/testData/quickfix/modifiers/beforeNestedClassNotAllowed.kt

@@ -0,0 +1,7 @@
+// "Add 'inner' modifier" "true"
+class A() {
+    inner class B() {
+        class <caret>C() {
+        }
+    }
+}