Fix installing of SIMD object on global object.

Fix installing of SIMD object on global object.

We should not install the SIMD object on the global object unless
support for SIMD is actually turned on by the flag. Otherwise calling
SIMD.Float32x4() will hit unreachable code. We accidentally SIMD.

R=rossberg@chromium.org

Committed: https://crrev.com/d4cd3f5ef32356be6717f6957933a354f18219e8
Cr-Commit-Position: refs/heads/master@{#29749}

[Michael Starzinger, 2015-07-20 09:40:33]

mstarzinger@chromium.org changed reviewers:
+ bbudge@chromium.org

[Michael Starzinger, 2015-07-20 09:40:33]

Andreas: PTAL.
Bill: FYI.

[rossberg, 2015-07-20 10:33:16]

lgtm

[Michael Starzinger, 2015-07-20 10:35:19]

The CQ bit was checked by mstarzinger@chromium.org

[commit-bot: I haz the power, 2015-07-20 10:35:27]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1240223002/1

[commit-bot: I haz the power, 2015-07-20 10:37:47]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-20 10:38:05]

Patchset 1 (id:??) landed as
https://crrev.com/d4cd3f5ef32356be6717f6957933a354f18219e8
Cr-Commit-Position: refs/heads/master@{#29749}

[bbudge-google, 2015-07-20 12:38:03]

bbudge@google.com changed reviewers:
+ bbudge@google.com

[bbudge-google, 2015-07-20 12:38:03]

LGTM thanks