[strong] Fix inlining issue

[strong] Fix inlining issue

The Hydrogen representation for binops was never changed to care about the
language mode. We thought this was ok, but it turns out we need to keep track
of it to make sure inlining doesn't mess with the "strongness" of binops.

Also added more rigorous inlining testing.

BUG=v8:3956
LOG=N

Committed: https://crrev.com/97bee8e9644151cf6560c79991b82862066e1eb7
Cr-Commit-Position: refs/heads/master@{#28253}

[conradw, 2015-05-05 17:23:52]

conradw@chromium.org changed reviewers:
+ rossberg@chromium.org

[conradw, 2015-05-05 18:43:49]

Patchset #1 (id:1) has been deleted

[conradw, 2015-05-05 20:01:27]

PTAL

[rossberg, 2015-05-06 10:38:03]

lgtm

[conradw, 2015-05-06 10:38:46]

The CQ bit was checked by conradw@chromium.org

[commit-bot: I haz the power, 2015-05-06 10:38:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1123043002/20001

[commit-bot: I haz the power, 2015-05-06 10:40:34]

Committed patchset #1 (id:20001)

[commit-bot: I haz the power, 2015-05-06 10:40:52]

Patchset 1 (id:??) landed as
https://crrev.com/97bee8e9644151cf6560c79991b82862066e1eb7
Cr-Commit-Position: refs/heads/master@{#28253}