MIPS: Fixed Hydrogen environment handling for mul-i ARM and ARM64.

MIPS: Fixed Hydrogen environment handling for mul-i ARM and ARM64.

Port a7d67a64f11100434b196143e2ba516f8c13697a

Original commit message:
The whole logic in DoMul makes me cry, so I made only the minimal
change to fix the issue...

BUG=v8:451322
LOG=y

Committed: https://crrev.com/0ae9eb038fd47f94493141ebf6144363363fac6b
Cr-Commit-Position: refs/heads/master@{#26277}

[balazs.kilvady, 2015-01-26 12:28:17]

balazs.kilvady@imgtec.com changed reviewers:
+ akos.palfi@imgtec.com, danno@chromium.org, dusan.milosavljevic@imgtec.com,
gergely.kis@imgtec.com, paul.lind@imgtec.com, svenpanne@chromium.org

[paul.l..., 2015-01-26 15:15:25]

LGTM.

[balazs.kilvady, 2015-01-26 15:46:30]

The CQ bit was checked by balazs.kilvady@imgtec.com

[commit-bot: I haz the power, 2015-01-26 15:46:40]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/879473002/1

[commit-bot: I haz the power, 2015-01-26 16:16:00]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-26 16:16:11]

Patchset 1 (id:??) landed as
https://crrev.com/0ae9eb038fd47f94493141ebf6144363363fac6b
Cr-Commit-Position: refs/heads/master@{#26277}