CppEditor: Run test cases for virtual functions also with clangd

This uncovered some bugs, of which we fixed the ones that we could do
something about.

Change-Id: Id8494793bec4d25635bf920133d9f9331bd36228
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/cpptools/cppvirtualfunctionassistprovider.cpp

@@ -113,7 +113,7 @@ public:
 
         auto *hintItem = new VirtualFunctionProposalItem(Utils::Link());
         hintItem->setText(QCoreApplication::translate("VirtualFunctionsAssistProcessor",
-                                                      "...searching overrides"));
+                                                      "collecting overrides ..."));
         hintItem->setOrder(-1000);
 
         QList<AssistProposalItemInterface *> items;