MIPS: Fixing floating point register clobbering

MIPS: Fixing floating point register clobbering

Fixing floating point register clobbering for MIPSr6 (32 and 64)
due to using of f31 floating point register as double compare register,
without saving the value of the register before using it.

TEST=cctest/test-debug/*
BUG=

Committed: https://crrev.com/2d8d02f5558386438c3765146edecf5c5706fba3
Cr-Commit-Position: refs/heads/master@{#30765}

[ivica.bogosavljevic, 2015-09-15 13:02:30]

ivica.bogosavljevic@imgtec.com changed reviewers:
+ akos.palfi@imgtec.com, balazs.kilvady@imgtec.com, paul.lind@imgtec.com

[paul.l..., 2015-09-15 14:24:50]

LGTM.

[ivica.bogosavljevic, 2015-09-16 08:02:43]

The CQ bit was checked by ivica.bogosavljevic@imgtec.com

[commit-bot: I haz the power, 2015-09-16 08:02:49]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1346623002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1346623002/1

[commit-bot: I haz the power, 2015-09-16 08:04:40]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-09-16 08:04:40]

Try jobs failed on following builders:
  v8_android_arm_compile_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_android_arm_compile_rel/...)

[ivica.bogosavljevic, 2015-09-16 11:49:07]

The CQ bit was checked by ivica.bogosavljevic@imgtec.com

[commit-bot: I haz the power, 2015-09-16 11:49:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1346623002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1346623002/1

[commit-bot: I haz the power, 2015-09-16 12:15:20]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-09-16 12:15:41]

Patchset 1 (id:??) landed as
https://crrev.com/2d8d02f5558386438c3765146edecf5c5706fba3
Cr-Commit-Position: refs/heads/master@{#30765}