MIPS: [turbofan] Introduce optional Float64Min and Float64Max machine operators.

MIPS: [turbofan] Introduce optional Float64Min and Float64Max machine operators.

Port 99f8d57f3c5d967bc3b10356b22d7ec7be55e89f

Original commit message:
Basically recognize certain x < y ? x : y constructs and turn that into
Float64Min/Float64Max operations, if the target machine supports that.
On x86 we lower to (v)minsd/(v)maxsd.

BUG=

Committed: https://crrev.com/323ec9e8bda05bdc0a0f7eb55e910f7c28b2e1bc
Cr-Commit-Position: refs/heads/master@{#27168}

[balazs.kilvady, 2015-03-12 16:06:18]

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

[paul.l..., 2015-03-12 16:21:40]

lgtm

[balazs.kilvady, 2015-03-12 16:23:32]

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

[commit-bot: I haz the power, 2015-03-12 16:23:43]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1006513002/1

[commit-bot: I haz the power, 2015-03-12 16:43:44]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-12 16:43:57]

Patchset 1 (id:??) landed as
https://crrev.com/323ec9e8bda05bdc0a0f7eb55e910f7c28b2e1bc
Cr-Commit-Position: refs/heads/master@{#27168}