This reduces the overhead of typed lowering, because we lower
JSToBoolean/JSUnaryNot directly if possible, instead of first lowering
to AnyToBoolean, and then letting the SimplifiedOperatorReducer do the
further lowering.

Also remove some obsolete tests from the cctest suite that have since
been removed by proper unittests. And improve unitttest coverage for the
typed lowering cases.

R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/999173003

Cr-Commit-Position: refs/heads/master@{#27295}