Instead of doing the dance via JSStrictEqual for comparisons with null,
undefined or the hole, we can just go to ReferenceEqual directly. Also
avoid the Select(x, false, true) dance for negation and use BooleanNot
directly.

R=mstarzinger@chromium.org

Review-Url: https://codereview.chromium.org/2646763004
Cr-Commit-Position: refs/heads/master@{#42500}