Debugger: Modernize

modernize-use-auto
modernize-use-nullptr
modernize-use-override
modernize-use-using
modernize-use-default-member-init
modernize-use-equals-default

Change-Id: I91a6874f0d7b94e9079ab4ef07c23c60c80be9c0
Reviewed-by: Christian Stenger <christian.stenger@qt.io>
Reviewed-by: hjk <hjk@qt.io>

src/plugins/debugger/watchhandler.h

@@ -37,14 +37,14 @@ class DebuggerCommand;
 class DebuggerEngine;
 class WatchModel;
 
-typedef QVector<DisplayFormat> DisplayFormats;
+using DisplayFormats = QVector<DisplayFormat>;
 
 class WatchModelBase : public Utils::TreeModel<WatchItem, WatchItem>
 {
     Q_OBJECT
 
 public:
-    WatchModelBase() {}
+    WatchModelBase() = default;
 
 signals:
     void currentIndexRequested(const QModelIndex &idx);