anv: group as many command buffers into a single execbuf
When semaphores are not involved, try to batch things up as much as possible across VkSubmitInfo and also batch command buffers within a VkSubmitInfo. v2: Reuse anv_cmd_buffer_is_chainable() Signed-off-by:Lionel Landwerlin <lionel.g.landwerlin@intel.com> Reviewed-by:
Kenneth Graunke <kenneth@whitecape.org> Part-of: <mesa/mesa!2371>