[turbofan] Add language mode to JSCallFunction operator.

[turbofan] Add language mode to JSCallFunction operator.

Also do some drive-by-cleanup to the unittests.

R=svenpanne@chromium.org

Committed: https://chromium.googlesource.com/v8/v8/+/2d827809e0a20fc60faa3be87ba9357bbded4a4c

[Benedikt Meurer, 2015-04-27 10:28:28]

Hey Sven,

As discussed offline, here's the language mode for JSCallFunction. Please take a
look.

Thanks,
Benedikt

[Sven Panne, 2015-04-27 10:38:39]

The CQ bit was checked by svenpanne@chromium.org

[Sven Panne, 2015-04-27 10:38:39]

lgtm

[commit-bot: I haz the power, 2015-04-27 10:38:46]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1107883002/1

[Benedikt Meurer, 2015-04-27 10:45:12]

Committed patchset #1 (id:1) manually as
2d827809e0a20fc60faa3be87ba9357bbded4a4c (presubmit successful).

[commit-bot: I haz the power, 2015-04-27 10:45:13]

Patchset 1 (id:??) landed as
https://crrev.com/2d827809e0a20fc60faa3be87ba9357bbded4a4c
Cr-Commit-Position: refs/heads/master@{#28066}

[Michael Achenbach, 2015-04-27 10:59:30]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1103143002/ by machenbach@chromium.org.

The reason for reverting is: [Sheriff] breaks win compile and was committed
manually.