[turbofan] Fix value output count for the Start node.

[turbofan] Fix value output count for the Start node.

The value output count for Start is currently off by 1 for code stubs,
because the CommonOperatorBuilder hardcodes the receiver parameter.

R=mstarzinger@chromium.org

Committed: https://crrev.com/870ce53a53fb53c651b930c0d57e4ddae008568a
Cr-Commit-Position: refs/heads/master@{#29490}

[Benedikt Meurer, 2015-07-06 11:36:33]

Hey Michi,

The cleanup we talked about. This way context specialization won't need a magic
index input.
Please take a look.

Thanks,
Benedikt

[Michael Starzinger, 2015-07-06 11:39:47]

LGTM.

[Benedikt Meurer, 2015-07-06 11:40:32]

The CQ bit was checked by bmeurer@chromium.org

[Benedikt Meurer, 2015-07-06 11:40:32]

The patchset sent to the CQ was uploaded after l-g-t-m from
mstarzinger@chromium.org
Link to the patchset: https://codereview.chromium.org/1217553005/#ps20001
(title: "Fix test-run-stubs.cc")

[commit-bot: I haz the power, 2015-07-06 11:40:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1217553005/20001

[commit-bot: I haz the power, 2015-07-06 12:11:54]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-07-06 12:12:11]

Patchset 2 (id:??) landed as
https://crrev.com/870ce53a53fb53c651b930c0d57e4ddae008568a
Cr-Commit-Position: refs/heads/master@{#29490}