MIPS: Fix MacroAssembler::AssertFunction()

MIPS: Fix MacroAssembler::AssertFunction()

Porting mistake in ccbb4ff0 '[builtins] Unify the various versions of [[Call]]
with a Call builtin.', which only showed as debug assertion in later commit
db2ba190 '[runtime] Replace many buggy uses of %_CallFunction with %_Call.'

Use temporary register rather than push/pop of 'object' register.

BUG=
TEST=cctest/test-api/SetFunctionEntryHook, cctest/test-serialize/PerIsolateSnapshotBlobs, ...

Committed: https://crrev.com/444a933931b405bd33485e8c299ee850b47a9531
Cr-Commit-Position: refs/heads/master@{#30643}

[paul.l..., 2015-09-08 18:32:39]

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

[paul.l..., 2015-09-08 18:32:40]

PTAL

[akos.palfi.imgtec, 2015-09-08 18:49:58]

LGTM

[paul.l..., 2015-09-08 18:50:25]

The CQ bit was checked by paul.lind@imgtec.com

[commit-bot: I haz the power, 2015-09-08 19:02:39]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1309163006/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1309163006/1

[Benedikt Meurer, 2015-09-08 19:13:46]

LGTM, thanks for fixing this.

[commit-bot: I haz the power, 2015-09-08 19:29:29]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-09-08 19:29:54]

Patchset 1 (id:??) landed as
https://crrev.com/444a933931b405bd33485e8c299ee850b47a9531
Cr-Commit-Position: refs/heads/master@{#30643}