Arrow functions have been enabled by default since the 4.5 branch. Review URL: https://codereview.chromium.org/1373633002 Cr-Commit-Position: refs/heads/master@{#31031}
R=dslomov@chromium.org, rossberg@chromium.org LOG=Y BUG=v8:2700 Review URL: https://codereview.chromium.org/1178523002 Cr-Commit-Position: refs/heads/master@{#28908}