V4: work around a bug in libc++'s std::vector<bool>
V4: work around a bug in libc++'s std::vector<bool>

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 <7388270c57edd0fabd71d8eb0322d66e3c40e57e@digia.com>
Reviewed-by: Lars Knoll <a812617a4072dcbeb80684eca0f369f0083af109@digia.com>
Reviewed-by: Simon Hausmann <a975102812d593b3191088e3d0aeaeb6f11dbcf5@digia.com>

matthewvogt/qtdeclarative,matthewvogt/qtdeclarative,matthewvogt/qtdeclarative,matthewvogt/qtdeclarative,matthewvogt/qtdeclarative,matthewvogt/qtdeclarative,matthewvogt/qtdeclarative,matthewvogt/qtdeclarative