It may return null during program exit, due to QCoreGlobalData global
static already having been destroyed. If that's the case, QTextStream
needs to fall back to Latin 1, like QString::toLocal8Bit and
fromLocal8Bit already do.
Task-number: QTBUG-38316
Change-Id: I5949c8dec15b60f4a13b5d9307ed6abfc799fe20
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>