deps: backport 22c5e46 from V8

Checklist

• make -j4 test (UNIX), or vcbuild test nosign (Windows) passes
• commit message follows commit guidelines

Affected core subsystem(s)

deps

Description of change

This removes the diagnostic code for the issue described in https://bugs.chromium.org/p/chromium/issues/detail?id=454297. That issue is private, probably due to the fact that it contains information about a security vulnerability.

The original issue was fixed in V8 by https://codereview.chromium.org/1286343004, which was integrated into node v4.x with c4317257, so there's no need for the corresponding diagnostic code anymore.

Original commit message:

[heap] Remove debugging code of crbug/454297.

BUG=

Review URL: https://codereview.chromium.org/1420253002

Cr-Commit-Position: refs/heads/master@{#31523}

Fixes #7574 (closed).