deps: backport bc2e393 from v8 upstream
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.

PR-URL: https://github.com/nodejs/node/pull/3792
Reviewed-By: Trevor Norris <9cb5491eb5770dd8e0bf77a8a0335abf5f0488c5@gmail.com>
Reviewed-By: Fedor Indutny <2e687df1861dff46b1954016c7b2cad32e8742d4@gmail.com>
Reviewed-By: Ben Noordhuis <59bd0a3ff43b32849b319e645d4798d8a5d1e889@bnoordhuis.nl>

dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node