That configuration causes gcc to create non portable code and thus
should not be used.

Task-number: QTBUG-51938
Change-Id: Ib134bd0b12811c15805943180c41af8f411e6453
Reviewed-by: Andrew Knight <andrew.knight@intopalo.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>