This divergence bug is very similar to the one fixed in https://codereview.chromium.org/2522253002/, this time it is an oscillation between a cleared field and a new phi node. The page http://www.sears.com/clothing-shoes-jewelry-clothing-men-s-clothing-men-s-jeans/b-1325287370?Brand=LEE&filterList=Brand&sortOption=UNITS_HIGH_TO_LOW allows for a reliable reproduction.

This fix makes sure that once a field that generated a phi gets cleared, it always stays cleared.

BUG=chromium:670202

R=bmeurer@chromium.org

Review-Url: https://codereview.chromium.org/2599793002
Cr-Commit-Position: refs/heads/master@{#41922}