Similar to CheckNotAtStart, one can now apply an offset to the
CheckAtStart operation. Due to a recent change, all callsites of
CheckNotAtStart now need to pass an offset, whereas previously the
offset was just assumed to be zero.

Bug: chromium:996391
Change-Id: Ia59a584e93e5384479f05abddef7859b420b023a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1773272
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Auto-Submit: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63444}