Also make the output more helpful in the error case.

Bug: v8:11724
Change-Id: Ibb8bd328f936f3d4f847ba7e14adf9c30b9460f0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2903158
Auto-Submit: Georg Neis <neis@chromium.org>
Commit-Queue: Nico Hartmann <nicohartmann@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74691}