This reverts commit b1468242.

Reason for revert: breaking blink, v8:8480

Original change's description:
> heap: Move embedder epilogue after first round of weak callbacks
> 
> Bug: chromium:843903, chromium:903586
> Change-Id: I0441ab2cc0fcc0b2cb411be0c92860c64d808324
> Reviewed-on: https://chromium-review.googlesource.com/c/1340254
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#57604}

TBR=ulan@chromium.org,mlippautz@chromium.org

Change-Id: I4f72fb4f6060d814d09fa9d75ff41b5e236c8505
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:843903, chromium:903586
Reviewed-on: https://chromium-review.googlesource.com/c/1342922Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57631}