Segfault on some applications using qt5

[BERTRAND Joël]

	Some news.

	I have rebuilt qt5 (5.14.2) from sources with debug symbols. Now, I see
okular aborts in :

(gdb) bt
#0  0x000000080163fa20 in qt_memfillXX_avx2(unsigned char*, long long
__vector(4), long long) () from /root/qt5/lib/libQt5Gui.so.5
#1  0x00000008018bc2d5 in fillRect_normalized(QRect const&, QSpanData*,
QRasterPaintEnginePrivate*) () from /root/qt5/lib/libQt5Gui.so.5
#2  0x00000008018bdcd6 in QRasterPaintEngine::fillRect(QRectF const&,
QSpanData*) () from /root/qt5/lib/libQt5Gui.so.5
#3  0x00000008018e1a9c in QPainter::fillRect(QRect const&, QBrush const&) ()
   from /root/qt5/lib/libQt5Gui.so.5
#4  0x00000008010c04be in fillRegion(QPainter*, QRegion const&, QBrush
const&)
    () from /root/qt5/lib/libQt5Widgets.so.5
#5  0x00000008010c017f in QWidgetPrivate::paintBackground(QPainter*,
QRegion const&, QFlags<QWidgetPrivate::DrawWidgetFlag>) const ()
   from /root/qt5/lib/libQt5Widgets.so.5

	I'm rebuilding qt without optimization (avx2), but help will be welcome.

	Best regards,

	JKB