work around MSVC2010 ICE

Task-number: QTBUG-43394
Change-Id: Ifffcc0cf9109b76d79f603a13792d7fd9979761c
Reviewed-by: Joerg Bornemann <joerg.bornemann@theqtcompany.com>
(cherry picked from qtbase/87eb3ea1904756362ce5474838b25b5b00193dc5)