PPC: [stubs] Don't pass name to Load/StoreGlobalViaContext stubs.

PPC: [stubs] Don't pass name to Load/StoreGlobalViaContext stubs.

Port 5dff4bdff06c0463db1e876af7541af2b715392c

Original commit message:
    No need to pass the name explicitly to the stubs; the runtime can
    extract the name from the ScopeInfo (the extension of the
    ScriptContext) on-demand easily without any performance impact.

R=bmeurer@chromium.org, dstence@us.ibm.com, michael_dawson@ca.ibm.com
BUG=
NOTREECHECKS=true

Committed: https://crrev.com/d8b31d881fe5bd118d748e962de1925b78d89563
Cr-Commit-Position: refs/heads/master@{#29906}

[dstence, 2015-07-28 16:23:29]

lgtm

[MTBrandyberry, 2015-07-28 16:29:58]

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

[commit-bot: I haz the power, 2015-07-28 16:30:10]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1258273002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1258273002/1

[Michael Hablich, 2015-07-30 07:26:42]

The CQ bit was unchecked by hablich@chromium.org

[Michael Hablich, 2015-07-30 07:26:52]

The CQ bit was checked by hablich@chromium.org

[commit-bot: I haz the power, 2015-07-30 07:27:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1258273002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1258273002/1

[commit-bot: I haz the power, 2015-07-30 07:28:45]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-30 07:29:06]

Patchset 1 (id:??) landed as
https://crrev.com/d8b31d881fe5bd118d748e962de1925b78d89563
Cr-Commit-Position: refs/heads/master@{#29906}