Add Q_ENUM for QCompleter enums

This is necessary in order to use the properties of QCompleter that use
these enums.

Change-Id: I9f7edfc1137f200810b6bc98d27709695f37de5d
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

src/widgets/util/qcompleter.h

@@ -75,12 +75,14 @@ public:
         UnfilteredPopupCompletion,
         InlineCompletion
     };
+    Q_ENUM(CompletionMode)
 
     enum ModelSorting {
         UnsortedModel = 0,
         CaseSensitivelySortedModel,
         CaseInsensitivelySortedModel
     };
+    Q_ENUM(ModelSorting)
 
     QCompleter(QObject *parent = nullptr);
     QCompleter(QAbstractItemModel *model, QObject *parent = nullptr);