Documentation for pipe_context::flush states:
"NOTE: use screen->fence_reference() (or equivalent) to transfer
new fence ref to **fence, to ensure that previous fence is unref'd"
Hence we need to unref previous out_fence.
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Documentation for pipe_context::flush states:
"NOTE: use screen->fence_reference() (or equivalent) to transfer
new fence ref to **fence, to ensure that previous fence is unref'd"
Hence we need to unref previous out_fence.