Handle the case where getting a value in the iterable object that
encodes the values throws an exception.

R=ahaas@chromium.org

Bug: chromium:1347073
Change-Id: Ie660ab04148d5fd3508397ae6e08130496f61b74
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3788097
Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81974}