Allows writing of output error to json output path specified.

Bug: chromium:985959
Change-Id: I4bbc94dbc8b0c21f1ce75e722c69fab18eeb1f01
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1710205
Commit-Queue: Debrian Figueroa <debrian@google.com>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62858}