This should fix the Turbofan Octane/Mandreel regression introduced by

commit 9ea551aa
Author: jarin <jarin@chromium.org>
Date:   Sun Nov 22 05:45:38 2015 -0800

    [turbofan] Simplify lowering of number addition.

    Review URL: https://codereview.chromium.org/1471533002

    Cr-Commit-Position: refs/heads/master@{#32159}

Review URL: https://codereview.chromium.org/1477803002

Cr-Commit-Position: refs/heads/master@{#32304}