Use these check points to optimize comparisons where we already know
that one side cannot be a String (or turn into a string via
ToPrimitive).

Also remove bunch of useless DoNotCrash tests for the scheduler that are
painful to maintain and add almost no value.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/1140583004

Cr-Commit-Position: refs/heads/master@{#28383}