I also used the opportunity to clean up the loop peeler a bit by making the
class stateful, to avoid passing long argument lists around.

Bug: v8:5864
Change-Id: I2e034c6eabd381b01e15cf3e6aa3ce7b14e7b3d8
Reviewed-on: https://chromium-review.googlesource.com/822933
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50067}