The {index} argument to {Peek} is unused. Other {Peek} methods use it to
generate the error message, but {Peek} without expected type does not
type check anything so it stays unused.

R=manoskouk@chromium.org

Change-Id: I979063f707f7305987220d6c192db7e679d930ce
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3490930Reviewed-by: Manos Koukoutos <manoskouk@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79280}