QmlDesigner.NodeInstances: Use v8 private headers

Change-Id: I4c0d8e08a22ee0c5b2602cc7d877071010fd9f88
Reviewed-on: http://codereview.qt.nokia.com/3976Reviewed-by: Thomas Hartmann <Thomas.Hartmann@nokia.com>
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>

share/qtcreator/qml/qmlpuppet/qml2puppet/qml2puppet.pro

@@ -8,7 +8,7 @@ contains (QT_CONFIG, webkit) {
     QT += webkit
 }
 
-QT += core-private declarative-private gui-private script-private
+QT += core-private declarative-private gui-private script-private v8-private
 
 DEFINES += QWEAKPOINTER_ENABLE_ARROW