unreachable was true if the last block is unreachable in the linear cfg,
but it should also be true if it is unreachable in the logical cfg.
Fixes dEQP-VK.graphicsfuzz.for-with-ifs-and-return
Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Fixes: 8d8c864beb
('aco: improve check for unreachable loop continue blocks')
Reviewed-by: Daniel Schürmann <daniel@schuermann.dev>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4764>