MIPS64: Fix after [turbofan] Avoid unnecessary write barriers and improve code generation.

MIPS64: Fix after [turbofan] Avoid unnecessary write barriers and improve code generation.

Use 64-bit add for address.

TEST=mjsunit/sparse-array.js, others.
BUG=

Committed: https://crrev.com/6e0aa37c7e7a6a2271c2f0406206501691bd57ea
Cr-Commit-Position: refs/heads/master@{#31937}

[paul.l..., 2015-11-11 06:19:19]

paul.lind@imgtec.com changed reviewers:
+ akos.palfi@imgtec.com, balazs.kilvady@imgtec.com, bmeurer@chromium.org

[paul.l..., 2015-11-11 06:19:19]

PTAL. Benedikt, could you please commit this as well? I suspect my usual
reviewers are still sleeping :-)

[Benedikt Meurer, 2015-11-11 06:20:22]

The CQ bit was checked by bmeurer@chromium.org

[Benedikt Meurer, 2015-11-11 06:20:22]

lgtm

[commit-bot: I haz the power, 2015-11-11 06:20:27]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1435793002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1435793002/1

[commit-bot: I haz the power, 2015-11-11 06:38:29]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-11-11 06:38:52]

Patchset 1 (id:??) landed as
https://crrev.com/6e0aa37c7e7a6a2271c2f0406206501691bd57ea
Cr-Commit-Position: refs/heads/master@{#31937}