The parent of instantiation of nested class of template class
should be the instantiation of enclosing template class.

To prevent the infinite loop for case with local typedef of enclosing
template we should not change a parent of typedefed instatiation of
enclosing template. Example:
template <typename T>
struct Enclosing
{
  typedef Enclosing<T> EnclosingT;// first case
  struct Nested
  {
    typedef Enclosing<T> EnclosingT;// second case
  };
};

Task-number: QTCREATORBUG-11752
Task-number: QTCREATORBUG-11999
Change-Id: Iadd7b5ef73ee0c4881f59c9dabfe03339f55827b
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@digia.com>