Amends 642f799fc6 to avoid unnecessary
copies in between the calls to the QFunctorSlotObject construcotr. We
can't use a univeral reference in the QFunctorSlotObject constructor
as the call is not deduced. So provide two overloads for lvalue and
rvalue references instead.
The compile check in the test now no longer fails as we delay the
storage until one level later, but that's acceptable.
Change-Id: Ide95b4a73c70f6f47698dd1e95138aa5d48ee95d
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
6e2bba71bb