C++ editor: support nested class of enclosing template

Fixing:
* highlighting
* tooltips
* find usage
* selecting

Task-number: QTCREATORBUG-8245
Change-Id: I6e900799e43126706125b7e424567fca2b2c223e
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@digia.com>

src/plugins/cppeditor/cppelementevaluator.cpp

@@ -118,6 +118,8 @@ void CppElementEvaluator::execute()
 
         TypeOfExpression typeOfExpression;
         typeOfExpression.init(doc, snapshot);
+        // make possible to instantiate templates
+        typeOfExpression.setExpandTemplates(true);
         const QList<LookupItem> &lookupItems = typeOfExpression(expression.toUtf8(), scope);
         if (lookupItems.isEmpty())
             return;