radeonsi: do not do two full flushes on every compute dispatch

radeonsi: do not do two full flushes on every compute dispatch

v2: Add more CS_PARTIAL_FLUSH events.

Essentially every place with waits on finishing for pixel shaders
also has a write after read hazard with compute shaders.

Invalidating L2 waits implicitly on pixel and compute shaders,
so, we don't need a CS_PARTIAL_FLUSH for switching FBO.

v3: Add CS_PARTIAL_FLUSH events even if we already have INV_GLOBAL_L2.

According to Marek the INV_GLOBAL_L2 events don't wait for compute
shaders to finish, so wait for them explicitly.

Signed-off-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>