Classify all test262-es6 failures

File bugs for all failing tests in test262-es6.

There are still some old "needs investigation" failures that I didn't
investigate.

BUG=N
LOG=N
R=littledan@chromium.org, adamk@chromium.org

Review URL: https://codereview.chromium.org/1209163002

Cr-Commit-Position: refs/heads/master@{#29329}