They have a separate type that we can't recognize directly, but we
can check if we can recognize the QFlags<T> form, though we have to
add a lot of template-conditions to avoid triggering QFlags static
asserts.
Change-Id: I00853682c5376dd3cc411ff151f47bce2389e277
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>