MIPS: Replace numeric_limits<>::lowest() in cctest-assembler*.cc

MIPS: Replace numeric_limits<>::lowest() in cctest-assembler*.cc

On Mac for the requested minimal version (10.5) only old stl (from gcc 4.2.1) can be used so unfortunately we can't use numeric_limits<>::lowest() which were added in 874c54e05e92e04590b1026b495108abfd6063b7

BUG=
TEST=cctest/test-assembler-mips64, cctest/test-assembler-mips

Committed: https://crrev.com/f51e507264799742304cbed7a8095525c5a0cfe1
Cr-Commit-Position: refs/heads/master@{#28907}

[balazs.kilvady, 2015-06-10 12:53:42]

balazs.kilvady@imgtec.com changed reviewers:
+ akos.palfi@imgtec.com, djordje.pesic@imgtec.com,
dusan.milosavljevic@imgtec.com, paul.lind@imgtec.com

[dusmil.imgtec, 2015-06-10 14:36:16]

LGTM.

[balazs.kilvady, 2015-06-10 15:19:32]

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

[commit-bot: I haz the power, 2015-06-10 15:19:38]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1175463003/1

[commit-bot: I haz the power, 2015-06-10 15:45:12]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-06-10 15:45:39]

Patchset 1 (id:??) landed as
https://crrev.com/f51e507264799742304cbed7a8095525c5a0cfe1
Cr-Commit-Position: refs/heads/master@{#28907}