Add an operator QVariant() to QRegExp to keep things at source compatible
as possible.
Add a hack to QVariant::load/save() to recognize the old typeid
for QRegExp and stream them correctly as long as the streaming operators
for QRegExp are registered.
Also move the datastream test for QRegExp to tst_qregexp, and adjust it to
the qvariant changes.
Change-Id: I120b38a7541b43ec07a21b17f7f35c55f071eb75
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>