vsdg: add an output to objdef node
vsdg: add an output to objdef node

It makes no sense that the objdef node has no output. We temporarily give
it a state type as output so that we can connect to the introduced graph tail
node.

Signed-off-by: Helge Bahmann <c5618920f622561f9c0ec5c42219c4c08180149f@chaoticmind.net>

phate/jive,phate/jive,phate/jive