Place inner enum into its parent's class object

#KT-2771 In Progress

ClassifierCollector now collects all enum declarations inside non-static
classes. After all declarations are done, it processes these enums: creates
a class object if it's not present, reports errors on each enum if a class
object is not allowed, and puts every enum into this class object otherwise,
recording this fact to trace.

compiler/tests/org/jetbrains/jet/codegen/EnumGenTest.java

@@ -155,4 +155,12 @@ public class EnumGenTest extends CodegenTestCase {
     public void testEntryWithInner() {
         blackBoxFile("enum/entrywithinner.kt");
     }
+
+    public void testInner() {
+        blackBoxFile("enum/inner.kt");
+    }
+
+    public void testInnerWithExistingClassObject() {
+        blackBoxFile("enum/innerWithExistingClassObject.kt");
+    }
 }