PPC: [turbofan] Add new Float32Abs and Float64Abs operators.

PPC: [turbofan] Add new Float32Abs and Float64Abs operators.

Port 9af9f1d0262e2dab66c62331a03f6a76504f3866

Original commit message:
These operators compute the absolute floating point value of some
arbitrary input, and are implemented without any branches (i.e. using
vabs on arm, and andps/andpd on x86).

R=mbrandy@us.ibm.com

BUG=

Committed: https://crrev.com/c00de38657643f7c44d70d7217cc4ea0ec92eeeb
Cr-Commit-Position: refs/heads/master@{#27727}

[michael_dawson, 2015-04-09 21:35:09]

Catching up, next PPC port

[MTBrandyberry, 2015-04-09 21:43:20]

On 2015/04/09 21:35:09, michael_dawson wrote:
> Catching up, next PPC port

lgtm

[michael_dawson, 2015-04-09 21:48:32]

The CQ bit was checked by michael_dawson@ca.ibm.com

[commit-bot: I haz the power, 2015-04-09 21:49:09]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1072963002/1

[commit-bot: I haz the power, 2015-04-09 22:29:34]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-09 22:29:40]

Patchset 1 (id:??) landed as
https://crrev.com/c00de38657643f7c44d70d7217cc4ea0ec92eeeb
Cr-Commit-Position: refs/heads/master@{#27727}