radv: Implement conditional rendering for async compute queue.

radv: Implement conditional rendering for async compute queue.

MEC (the compute queue firmware) does not support real
predication, so we have to emulate that using COND_EXEC
packets before each dispatch.

Additionally, COND_EXEC doesn't have an inverted mode, so
in order to support inverted mode conditional rendering, we
allocate a new piece of memory in which we invert the condition.

Cc: mesa-stable
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/6533
Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16653>