title: Qt 5.5 (Q_ENUM causing compile error)
body: <p>I've just upgraded Qt from 5.3.2 to 5.5.0.  A project (which uses QAbstractTableModel) which compiles just fine in 5.3.2 does not compile in 5.5.0, reporting the following error (numerous times):</p>
  
  <pre><code>/usr/local/Qt-5.5.0/include/QtCore/qabstractitemmodel.h:241: error: ISO C++     forbids declaration of 'Q_ENUM' with no type [-fpermissive]
       Q_ENUM(LayoutChangeHint)
                          ^
  </code></pre>
  
  <p>The errors are entirely in Qt's files, not mine.  I'm using gcc491.  Below is a few interesting bits from my project file.  Any ideas?</p>
  
  <pre><code>TEMPLATE = app
  TARGET = MyApp
  QT += core widgets gui
  QMAKE_CXXFLAGS += -g -std=c++11
  </code></pre>