Fix clang build, mostly shadowing warnings

src/private/widgets/TabBarWidget.cpp

@@ -34,6 +34,7 @@
 #include <QProxyStyle>
 
 namespace KDDockWidgets {
+namespace { // anonymous namespace to silence -Wweak-vtables
 class MyProxy : public QProxyStyle
 {
 public:
@@ -63,6 +64,7 @@ public:
     }
 };
 }
+}
 
 using namespace KDDockWidgets;