Allow for optimized code map to have zero entries.

Allow for optimized code map to have zero entries.

This allows the optimized code map to contain no context-dependent
entries, but still hold one context-independent entry. This is a
precursor to extending the lifetime of the context-independent entry.

R=mvstanton@chromium.org

Committed: https://crrev.com/1c857357102547580d7b8444e4dc81c2113da34d
Cr-Commit-Position: refs/heads/master@{#29788}

[mvstanton, 2015-07-22 07:28:04]

Totally awesome!
LGTM.
Do you have a test that creates turbofan context-independent code that gets
found with this new approach?
Thanks,
--Michael

[Michael Starzinger, 2015-07-22 08:01:02]

On 2015/07/22 07:28:04, mvstanton wrote:
> Totally awesome!
> LGTM.
> Do you have a test that creates turbofan context-independent code that gets
> found with this new approach?
> Thanks,
> --Michael

As discussed offline, I'll add cctest cases.

[Michael Starzinger, 2015-07-22 08:33:08]

Added test case. PTAL.

[Michael Starzinger, 2015-07-22 11:44:03]

The CQ bit was checked by mstarzinger@chromium.org

[Michael Starzinger, 2015-07-22 11:44:04]

The patchset sent to the CQ was uploaded after l-g-t-m from
mvstanton@chromium.org
Link to the patchset: https://codereview.chromium.org/1249543005/#ps20001
(title: "Added test case.")

[commit-bot: I haz the power, 2015-07-22 11:44:11]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1249543005/20001

[commit-bot: I haz the power, 2015-07-22 11:46:09]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-07-22 11:47:04]

Patchset 2 (id:??) landed as
https://crrev.com/1c857357102547580d7b8444e4dc81c2113da34d
Cr-Commit-Position: refs/heads/master@{#29788}