This adds a new binary block coverage mode (in addition to the existing count
block coverage), as well as a few transformation passes to reduce the number of
uselessly reported ranges.

Bug: v8:6000
Change-Id: I4fb234ca015990d00aa2f1dccb87f76ba4748994
Reviewed-on: https://chromium-review.googlesource.com/552642
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46463}