PPC: [turbofan] Move JSCallFunction specialization to JSCallReducer.

PPC: [turbofan] Move JSCallFunction specialization to JSCallReducer.

Port e5edd66d070952ad4243acf14aa7cc161be7fe18

Original commit message:
    This is the first part to refactoring the JSNativeContextSpecialization
    class, which has grown way too big recently.

    Also don't collect cross context feedback for the CallIC in general.
    Neither TurboFan nor Crankshaft can make any use of cross context
    JSFunction feedback that is collected by the CallIC, so there's no
    point in gathering that feedback at all (it just complicates the
    checking that is necessary in the compilers). What we should do
    instead at some point (when Crankshaft becomes less important) is
    to collect the SharedFunctionInfo as feedback for those cases.

R=bmeurer@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=v8:4470
LOG=n

Committed: https://crrev.com/5019ce6ef32f585a9304a9767358fbf52c3852fb
Cr-Commit-Position: refs/heads/master@{#32059}

[MTBrandyberry, 2015-11-17 17:48:57]

The CQ bit was checked by mbrandy@us.ibm.com to run a CQ dry run

[commit-bot: I haz the power, 2015-11-17 17:49:06]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1455663002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1455663002/1

[commit-bot: I haz the power, 2015-11-17 18:06:42]

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

[commit-bot: I haz the power, 2015-11-17 18:06:42]

Dry run: This issue passed the CQ dry run.

[JoranSiu, 2015-11-17 19:40:09]

On 2015/11/17 18:06:42, commit-bot: I haz the power wrote:
> Dry run: This issue passed the CQ dry run.

lgtm

[MTBrandyberry, 2015-11-17 19:42:28]

The CQ bit was checked by mbrandy@us.ibm.com

[commit-bot: I haz the power, 2015-11-17 19:42:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1455663002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1455663002/1

[commit-bot: I haz the power, 2015-11-17 19:44:28]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-11-17 19:44:40]

Patchset 1 (id:??) landed as
https://crrev.com/5019ce6ef32f585a9304a9767358fbf52c3852fb
Cr-Commit-Position: refs/heads/master@{#32059}