[Intel-gfx] [RFC v2 i-g-t] Auto-tuned dummyload + recursive batch

[Abdiel Janulgue]

A lot of igt testcases need some GPU workload to make sure a race
window is big enough. Unfortunately having a fixed amount of
workload leads to spurious test failures or overtly long runtimes
on some fast/slow platforms. This library contains functionality
to submit GPU workloads that should consume exactly a specific
amount of time.

v2: Add recursive batch feature from Chris and use in gem_wait and
    kms_flip. I've retained the previous auto-tuned dummy load
    functions. Let me know if we need to drop those.

Abdiel Janulgue (3):
      lib: add igt_dummyload
      igt/gem_wait: Use new igt_spin_batch
      igt/kms_flip: Use new igt_spin_batch

 lib/Makefile.sources |   2 +
 lib/igt.h            |   1 +
 lib/igt_dummyload.c  | 613 +++++++++++++++++++++++++++
 lib/igt_dummyload.h  |  77 ++++
 tests/gem_wait.c     | 125 +-----
 tests/kms_flip.c     |   4 +-