tst_qsharedpointer: Fix auto test fail under Windows 7

tst_qsharedpointer: Fix auto test fail under Windows 7

The tst_QSharedPointer generate another Process to test some invalid
codes, and it expect that the prcoess will crash and return a non-zero
value.

The process which is a console application was linked to windows
subsystem, and QProcess seems can not get its return value. This
cause the unit test fail.

In addition, when the process crash under debug mode, a debug error
report-dialog will appear, which is very annoying, so I suppress it too.

Task-number: QTBUG-24160
Change-Id: Ia1c872d4515c83b0aa516bcfe3783f59797d2d49
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@nokia.com>