High-level testing of the struct drm_mm by verifying our handling of
weird requests to i915_vma_pin.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170213171558.20942-35-chris@chris-wilson.co.uk