Fix build failures in IB module when using older versions of Xcode.
Fix build failures in IB module when using older versions of Xcode.

Change-Id: I2c2fe4800dcc50e9760254f25c8e5e3e03b6f8f0
Reviewed-by: Joerg Bornemann <47777b9406dbddd02a3fdca8341789a013805a11@digia.com>

qt-labs/qbs,villytiger/qbs,qt-labs/qbs,qt-labs/qbs,gatzka/qt-labs-qbs,Distrotech/qbs,qt-labs/qbs,gatzka/qt-labs-qbs,Distrotech/qbs,gatzka/qt-labs-qbs,qt-labs/qbs,qtproject/qt-labs-qbs,villytiger/qbs,villytiger/qbs,qtproject/qt-labs-qbs,gatzka/qt-labs-qbs,villytiger/qbs,Distrotech/qbs,qtproject/qt-labs-qbs,qtproject/qt-labs-qbs,Distrotech/qbs,gatzka/qt-labs-qbs,qtproject/qt-labs-qbs,gatzka/qt-labs-qbs,villytiger/qbs,qt-labs/qbs,villytiger/qbs,qtproject/qt-labs-qbs,Distrotech/qbs,Distrotech/qbs,gatzka/qt-labs-qbs,Distrotech/qbs,qtproject/qt-labs-qbs,qt-labs/qbs