Reland "[test] Fix cctest path separators on Windows"

Reland "[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.

Original review: https://codereview.chromium.org/1348653003/

This reverts commit 5f44a9105980e7ca3a444c9c4293ee9442a8139f.

NOTRY=true

Committed: https://crrev.com/9516dccd41e7d60e7ca89375276ccc1eef03c2aa
Cr-Commit-Position: refs/heads/master@{#30798}

[Jakob Kummerow, 2015-09-17 12:45:26]

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

[Jakob Kummerow, 2015-09-17 12:45:26]

PTAL.

[Michael Achenbach, 2015-09-17 12:49:20]

lgtm

https://codereview.chromium.org/1356613002/diff/20001/test/mozilla/testcfg.py
File test/mozilla/testcfg.py (right):

https://codereview.chromium.org/1356613002/diff/20001/test/mozilla/testcfg.py...
test/mozilla/testcfg.py:100: reduce(os.path.join, testfilepath[:i], ""),
Fly-by code spottin:
reduce(os.path.join, testfilepath[:i], "")
should be the same as
os.path.join(*testfilepath[:i])

[Michael Achenbach, 2015-09-17 12:54:04]

I added notry, as the original passed CQ and mozilla isn't on it anyways.

[Michael Achenbach, 2015-09-17 12:58:58]

The CQ bit was checked by machenbach@chromium.org

[commit-bot: I haz the power, 2015-09-17 12:59:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1356613002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1356613002/20001

[commit-bot: I haz the power, 2015-09-17 13:01:04]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-09-17 13:01:22]

Patchset 2 (id:??) landed as
https://crrev.com/9516dccd41e7d60e7ca89375276ccc1eef03c2aa
Cr-Commit-Position: refs/heads/master@{#30798}