The ++operator of std::vector<bool>::iterator in libc++ has a bug when
using it on an iterator pointing to the last element. It will not be set
to ::end(), but beyond that. (It will be set to the first multiple of
the native word size that is bigger than size().)

See http://llvm.org/bugs/show_bug.cgi?id=19663



Task-number: QTBUG-39911
Change-Id: Ic244d9c90ee6b596261a6e322301c411a14820a8
Reviewed-by: Fawzi Mohamed <fawzi.mohamed@digia.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>