Fix fast-variants feature in test driver.

Fix fast-variants feature in test driver.

BUG=
R=bmeurer@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=25150

[Michael Achenbach, 2014-11-05 12:54:15]

machenbach@chromium.org changed reviewers:
+ bmeurer@chromium.org, jkummerow@chromium.org

[Michael Achenbach, 2014-11-05 12:54:16]

PTAL. This runs 2*9 tests now on tools/run-tests.py --arch ia32 --mode release
mjsunit/asm/embenchen --time --report

The report still looks weird and says 0 tests are expected to pass... maybe
because it doesn't know that expectation...

[Benedikt Meurer, 2014-11-05 12:54:52]

lgtm

[Michael Achenbach, 2014-11-05 13:05:40]

Committed patchset #1 (id:1) manually as 25150 (presubmit successful).

[Jakob Kummerow, 2014-11-05 13:07:52]

LGTM. Not too happy with the ever-increasing complexity, but I don't have a
better idea.

To fix --report, you'll have to adapt PrintReport in local/verbose.py, similar
to the existing line:

if list(o) == [statusfile.PASS]: passes += 1

Suggestion: Introduce a new predicate in statusfile.py: 

def IsPass(outcomes):
  return ((PASS in outcomes) and (not FAIL in outcomes) and
          (not CRASH in outcomes))

Then use that to replace the above line with:

if statusfile.IsPass(o): passes += 1