Runtime type information required to perform dynamic_cast is not available on aix platform unless code is compiled with -qrtti option

Assert failed thrown if running an application in debug mode on AIX computer.

This can be fixed by compiling Qt with the flag "qrtti".

The reason for this is:
Runtime type information required to perform dynamic_cast is not available on aix platform unless code is compiled with -qrtti option
Ref:
http://publib.boulder.ibm.com/infocenter/comphelp/v8v101/index.jsp?topic=%2Fcom.ibm.xlcpp8a.doc%2Fcompiler%2Fref%2Fruoptrtt.htm

Just add following lines to aix mkspecs qmake.conf:
QMAKE_CXXFLAGS_RTTI_ON = -qrtti
QMAKE_CXXFLAGS_RTTI_OFF = -qnortti