tu: implement sysmem vs gmem autotuner

The implementation is separate from Freedreno due to multithreading
support.

In Vulkan application may fill command buffer from many threads
and expect no locking to occur. We do introduce the possibility of
locking on renderpass end, however assuming that application
doesn't have a huge amount of slightly different renderpasses,
there would be minimal to none contention.

Other assumptions are:
- Application does submit command buffers soon after their creation.

Breaking the above may lead to some decrease in performance or
autotuner turning itself off.

The heuristic is too simplistic at the moment, to find a proper
one - we should run a bunch of traces with sysmem and gmem, and
build better heuristic from gathered data.

Signed-off-by: Danylo Piliaiev <dpiliaiev@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12128>