[test] Fix cctest path separators on Windows

[test] Fix cctest path separators on Windows

Now run-tests.py understands "suite/foo/bar" with forward slashes for
command-line test selection on all test suites on all platforms.

Previously, file-based suites like mjsunit also accepted "mjsunit/foo\bar";
that behavior is sacrificed here in favor of unification. For the cctest
suite, OTOH, it wasn't possible on Windows to select specific tests at all.

Committed: https://crrev.com/b36cfdb39ae648b49a1396c4f669df9b1f57996c
Cr-Commit-Position: refs/heads/master@{#30794}

[Jakob Kummerow, 2015-09-16 13:29:58]

jkummerow@chromium.org changed reviewers:
+ machenbach@google.com

[Jakob Kummerow, 2015-09-16 13:29:59]

PTAL.

The fix for cctest is in testsuite.py; all the testcfg.py changes are needed to
adapt to that change in global behavior.

[Michael Achenbach, 2015-09-17 08:40:57]

lg-tm for the motivation. But some stuff seems to not work as expected. E.g.
this:
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_rel/builds/9789/...

I also ran locally with run-tests.py ... mjsunit/apply with and without your
patch and got once 0 and once 4 tests run, while with mjsunit/asm/if-reduction
it seems to be different.

[Jakob Kummerow, 2015-09-17 09:24:47]

Thanks. What tripped me up was that "".split("x") == [""], as opposed to [],
which confused the following array concatenation. End result, mjsunit/foo/bar
would work, but mjsunit/bar wouldn't. Fixed in patch set 2 by avoiding splitting
and just working on strings.

[Jakob Kummerow, 2015-09-17 10:45:07]

The CQ bit was checked by jkummerow@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-09-17 10:45:11]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1348653003/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1348653003/20001

[commit-bot: I haz the power, 2015-09-17 11:10:16]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-09-17 11:10:17]

Dry run: This issue passed the CQ dry run.

[Michael Achenbach, 2015-09-17 11:12:24]

machenbach@chromium.org changed reviewers:
+ machenbach@chromium.org

[Michael Achenbach, 2015-09-17 11:12:24]

LGTM - thanks for that patch!

[Jakob Kummerow, 2015-09-17 11:20:27]

The CQ bit was checked by jkummerow@chromium.org

[commit-bot: I haz the power, 2015-09-17 11:20:40]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1348653003/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1348653003/20001

[commit-bot: I haz the power, 2015-09-17 11:24:01]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-09-17 11:24:19]

Patchset 2 (id:??) landed as
https://crrev.com/b36cfdb39ae648b49a1396c4f669df9b1f57996c
Cr-Commit-Position: refs/heads/master@{#30794}

[Jakob Kummerow, 2015-09-17 11:59:53]

A revert of this CL (patchset #2 id:20001) has been created in
https://codereview.chromium.org/1349163002/ by jkummerow@chromium.org.

The reason for reverting is: mozilla tests are failing on Windows.