Ensure mjsunit tests use dashes not underscores in flags directives.

Ensure mjsunit tests use dashes not underscores in flags directives.

BUG=chromium:505228
LOG=Y

Committed: https://crrev.com/cff8c9b9339111b1b807aceacf43235b36d1a98f
Cr-Commit-Position: refs/heads/master@{#29355}

[oth, 2015-06-29 15:42:02]

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

[commit-bot: I haz the power, 2015-06-29 15:42:16]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1219723002/1

[commit-bot: I haz the power, 2015-06-29 15:42:17]

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

[commit-bot: I haz the power, 2015-06-29 15:42:18]

Dry run: No L-G-T-M from a valid reviewer yet. Only full committers are
accepted.
Even if an L-G-T-M may have been provided, it was from a non-committer,
_not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[oth, 2015-06-29 15:48:35]

oth@chromium.org changed reviewers:
+ erikcorry@chromium.org, ishell@chromium.org, mstarzinger@chromium.org

[oth, 2015-06-29 15:48:36]

ishell@chromium.org: Please review changes in mjsunit and tools.

mstarzinger@chromium.org: Please review changes in mjsunit and tools.

[Igor Sheludko, 2015-06-29 15:56:14]

lgtm

[Michael Starzinger, 2015-06-29 15:58:47]

LGTM. Thanks!

[oth, 2015-06-29 16:40:32]

The CQ bit was checked by oth@chromium.org

[commit-bot: I haz the power, 2015-06-29 16:40:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1219723002/20001

[commit-bot: I haz the power, 2015-06-29 17:08:06]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-06-29 17:08:27]

Patchset 2 (id:??) landed as
https://crrev.com/cff8c9b9339111b1b807aceacf43235b36d1a98f
Cr-Commit-Position: refs/heads/master@{#29355}