This makes escape analysis treat all guard nodes in the graph as an
escaping use. We eventually want to properly handle guard nodes, this
just serves as a temporary workaround to get things going.

R=bmeurer@chromium.org
BUG=v8:602595
LOG=n

Review-Url: https://codereview.chromium.org/1972323004
Cr-Commit-Position: refs/heads/master@{#36286}