[turbofan] Recursively reduce new inputs of changed nodes.

[turbofan] Recursively reduce new inputs of changed nodes.

The GraphReducer should recurse into new inputs after a node was
changed. Most of the reducers already assume this behavior, and it
mostly worked by accident in many cases.

R=svenpanne@chromium.org

Committed: https://crrev.com/d0a7ef938ad54e5df867f14c27cb88a20786e573
Cr-Commit-Position: refs/heads/master@{#25861}

[Benedikt Meurer, 2014-12-17 10:15:13]

PTAL

[Sven Panne, 2014-12-17 10:23:12]

lgtm

[Benedikt Meurer, 2014-12-17 10:32:00]

Committed patchset #1 (id:1) manually as
d0a7ef938ad54e5df867f14c27cb88a20786e573 (presubmit successful).

[commit-bot: I haz the power, 2014-12-17 10:32:01]

Patchset 1 (id:??) landed as
https://crrev.com/d0a7ef938ad54e5df867f14c27cb88a20786e573
Cr-Commit-Position: refs/heads/master@{#25861}