Introduce a second decoder that simpler operates on a file so that it
can be run on dumped batchbuffers independent of the gpu.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Right now it requires a filename on the command line, (such as
/debug/dri/0/i915_batchbuffers). We plan to make it smarter in
the future by going out and collecting all the data it needs.