This has the upside that we'll never forget to add it to thrashing
tests. But we'll also never miss to move it when adding basic
functionality tests to existing binaries. Chris already started this
refining work in e.g.

commit d77eda66


Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Fri Nov 14 07:45:40 2014 +0000

    igt/gem_linear_blits: Require that we do the full test

by moving igt_skip_on_simulation into subtests.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>