We already do this (if we can't migrate them) when processing the
feedback but it could still happen that we find a deprecated map in the
graph later on.

Bug: chromium:996819, v8:7790
Change-Id: I3b9acc8bc21b5a9812235145b726ba3e53cc8957
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1784284Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63551}