[turbofan] Run DeadCodeElimination together with the advanced reducers.

[turbofan] Run DeadCodeElimination together with the advanced reducers.

This will immediately remove dead code from the graph once any of
the advanced reducers inserts it. Also changes the GraphReducer to
use the canonical Dead node for ReplaceWithValue.

R=jarin@chromium.org

Committed: https://crrev.com/88a40c5fb381924b1c0b2403dc582bceb2abe5da
Cr-Commit-Position: refs/heads/master@{#29217}

Committed: https://chromium.googlesource.com/v8/v8/+/64d6ab455d5749f7d8c93f99943e0ef67a2266bc

[Benedikt Meurer, 2015-06-23 08:24:28]

Hey Jaro,

Hopefully one of the last DCE CLs. Please take a look.

Thanks,
Benedikt

[Jarin, 2015-06-23 08:32:31]

lgtm

[Benedikt Meurer, 2015-06-23 08:32:39]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2015-06-23 08:32:45]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1206533002/1

[commit-bot: I haz the power, 2015-06-23 08:48:21]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-06-23 08:48:47]

Patchset 1 (id:??) landed as
https://crrev.com/88a40c5fb381924b1c0b2403dc582bceb2abe5da
Cr-Commit-Position: refs/heads/master@{#29217}

[Benedikt Meurer, 2015-06-23 09:38:46]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1200983004/ by bmeurer@chromium.org.

The reason for reverting is: Looks like this breaks Tests262..

[Benedikt Meurer, 2015-06-23 11:22:20]

Committed patchset #2 (id:20001) manually as
64d6ab455d5749f7d8c93f99943e0ef67a2266bc (presubmit successful).