This loop doesn't itself have a source position, so I wouldn't think
block coverage of it would make any sense (and all tests continue
to pass).

Removing this argument will make some refactoring I'm working on easier.

Bug: v8:6724
Change-Id: I4d6b734e077d9e61ad9362d07e57f155ec556221
Reviewed-on: https://chromium-review.googlesource.com/615385Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47375}