[stubs] Properly handle read-only properties in StoreGlobalViaContextStub.

[stubs] Properly handle read-only properties in StoreGlobalViaContextStub.

We don't need the hole check and slow runtime mode for read-only
properties this way.

R=ishell@chromium.org

Committed: https://crrev.com/cac64b9f634743f7f5311d4dca8d50157b10fab5
Cr-Commit-Position: refs/heads/master@{#29881}

[Benedikt Meurer, 2015-07-27 08:41:34]

Hey Igor,

Here's the optimization we were talking about this morning. Basically we can
handle read-only properties in fast path.
Please take a look.

Thanks,
Benedikt

[Benedikt Meurer, 2015-07-27 12:42:52]

Patchset #2 (id:20001) has been deleted

[Benedikt Meurer, 2015-07-27 12:42:58]

Patchset #1 (id:1) has been deleted

[Igor Sheludko, 2015-07-27 18:43:58]

The CQ bit was checked by ishell@chromium.org

[Igor Sheludko, 2015-07-27 18:43:58]

lgtm

[commit-bot: I haz the power, 2015-07-27 18:44:09]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1255133002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1255133002/40001

[commit-bot: I haz the power, 2015-07-27 18:45:32]

Committed patchset #1 (id:40001)

[commit-bot: I haz the power, 2015-07-27 18:45:43]

Patchset 1 (id:??) landed as
https://crrev.com/cac64b9f634743f7f5311d4dca8d50157b10fab5
Cr-Commit-Position: refs/heads/master@{#29881}