[turbofan] Use OSR value for innermost context value.

[turbofan] Use OSR value for innermost context value.

This changes the OsrValue insertion in the AstGraphBuilder to emit a
proper OsrValue instead of a special Parameter for the inner context
value at the OSR entry point.

R=titzer@chromium.org

Committed: https://crrev.com/21d330c89610d1ecd1419566f5cfcce1d7eee5fa
Cr-Commit-Position: refs/heads/master@{#29471}

[Michael Starzinger, 2015-07-03 13:13:29]

mstarzinger@chromium.org changed reviewers:
+ bmeurer@chromium.org

[Michael Starzinger, 2015-07-03 13:13:30]

Ben: PTAL.
Benedikt: FYI.

[titzer, 2015-07-03 16:43:20]

lgtm

[Benedikt Meurer, 2015-07-06 03:11:28]

The CQ bit was checked by bmeurer@chromium.org

[Benedikt Meurer, 2015-07-06 03:11:28]

lgtm

[commit-bot: I haz the power, 2015-07-06 03:11:40]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1213043005/1

[commit-bot: I haz the power, 2015-07-06 03:39:20]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-06 03:39:41]

Patchset 1 (id:??) landed as
https://crrev.com/21d330c89610d1ecd1419566f5cfcce1d7eee5fa
Cr-Commit-Position: refs/heads/master@{#29471}