Check for ClassKind in getClassifier() and getObjectDescriptor() implementations in java scopes

# KT-3124 fixed

compiler/frontend/src/org/jetbrains/jet/lang/resolve/scopes/JetScope.java

@@ -39,6 +39,9 @@ public interface JetScope {
         }
     };
 
+    /**
+     * Should not return object (class object or enum entry) class descriptors.
+     */
     @Nullable
     ClassifierDescriptor getClassifier(@NotNull Name name);