This reverts commit 181bbd5c.

Reason for revert: Still break Win tests https://ci.chromium.org/p/v8/builders/luci.v8.ci/V8%20Win64%20-%20debug/25096

Original change's description:
> Reland "[heap profiler] Refactor: Replace indices with HeapEntry*"
> 
> This is a reland of 69a502ce
> 
> TBR=ulan@chromium.org
> 
> Original change's description:
> > [heap profiler] Refactor: Replace indices with HeapEntry*
> >
> > Change-Id: I0c176f66711d45e2f59d527f3133a1afbf825ec3
> > Reviewed-on: https://chromium-review.googlesource.com/1229613
> > Commit-Queue: Alexei Filippov <alph@chromium.org>
> > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#56245}
> 
> Change-Id: I416da19eb38a1a55f5e2f5897062bc1ca454ac34
> Reviewed-on: https://chromium-review.googlesource.com/1246802
> Commit-Queue: Alexei Filippov <alph@chromium.org>
> Reviewed-by: Alexei Filippov <alph@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#56250}

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

Change-Id: I0d027d192a9354eb6157405566420e6aa38738c1
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/1248131Reviewed-by: Alexei Filippov <alph@chromium.org>
Commit-Queue: Alexei Filippov <alph@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56252}