Revert abd45154 "[Coverage] Add comment to skipped regions"

This casued assertions during Chromium builds. See comment on the code review

> Bug filled here: https://bugs.llvm.org/show_bug.cgi?id=45757.
> Add comment to skipped regions so we don't track execution count for lines containing only comments.
>
> Differential Revision: https://reviews.llvm.org/D84208

This reverts commit abd45154 and the
follow-up 87d72547.