C++: fix dereferencing of nested type and operator '->'

Fixed case:
template<class T>
struct List
{
  struct iterator
  {
    T *operator->() { return &t; }
    T t;
  };
  iterator begin() { return iterator(); }
};

struct Foo { int bar; };

void func()
{
  List<Foo> list;
  list.begin()->; // code completion doesn't work
}

Task-number: QTCREATORBUG-13799
Change-Id: I65e8d3092bbc9b01a5dbee241c24d95dd03fc670
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@theqtcompany.com>

src/libs/cplusplus/ResolveExpression.cpp

@@ -1078,8 +1078,9 @@ ClassOrNamespace *ResolveExpression::baseExpression(const QList<LookupItem> &bas
                 ClassOrNamespace *binding
                         = findClassForTemplateParameterInExpressionScope(r.binding(),
                                                                          ty);
+
                 if (! binding)
-                    binding = findClass(ty, scope);
+                    binding = findClass(ty, scope, r.binding());
 
                 if (binding){
                     // lookup for overloads of operator->