PPC: [es6] Re-implement rest parameters via desugaring.

PPC: [es6] Re-implement rest parameters via desugaring.

Port 510baeacbab311798d5e8795800ff773d00d062c

Original commit message:
    Kills the kRestParameter bailout/disabled optimization, and fixes
    lazily parsed arrow functions with rest parameters.

    Supercedes https://crrev.com/1235153006/

R=caitpotter88@gmail.com, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com, dstence@us.ibm.com
BUG=chromium:508074, v8:2160, v8:2700
LOG=N

Committed: https://crrev.com/9628d86085ddee83067c45046ed89e0e6f635d3f
Cr-Commit-Position: refs/heads/master@{#30574}

[caitp (gmail), 2015-09-03 17:13:40]

Non-owner LGTM

[dstence, 2015-09-03 18:12:10]

lgtm

[MTBrandyberry, 2015-09-03 18:16:42]

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

[commit-bot: I haz the power, 2015-09-03 18:16:49]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1318523006/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1318523006/1

[commit-bot: I haz the power, 2015-09-03 18:40:15]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-09-03 18:40:35]

Patchset 1 (id:??) landed as
https://crrev.com/9628d86085ddee83067c45046ed89e0e6f635d3f
Cr-Commit-Position: refs/heads/master@{#30574}