deps: backport bc2e393 from v8 upstream
Original commit message:
[tools] Make gen-postmortem-metadata.py more reliable
Instead of basing matches off of whitespace, walk the
inheritance chain and include any classes that inherit
from Object.
R=machenbach@chromium.org,jkummerow@chromium.org
NOTRY=true
Review URL: https://codereview.chromium.org/1435643002
Cr-Commit-Position: refs/heads/master@{#31964}
This adds some missing classes to postmortem info like JSMap and JSSet.
R=@indutny