This reverts commit b614cd78.

Reason for revert: https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Linux64/40448/overview

Original change's description:
> Reland "Reland "[heap] Add epoch to GC tracing events""
>
> This is a reland of 3238162d
>
> No changes since the last reland.
>
> Original change's description:
> > Reland "[heap] Add epoch to GC tracing events"
> >
> > This is a reland of be52501d
> >
> > Fix data race by not emitting the epoch for sweeper background jobs
> > at them moment.
> >
> > Original change's description:
> > > [heap] Add epoch to GC tracing events
> > >
> > > This CL adds the TRACE_GC_EPOCH macro, which adds the epoch as attribute
> > > to the trace event. Use TRACE_GC_EPOCH for top-level events, nested
> > > events can get the information from its parent.
> > >
> > > V8's GC needs an epoch for young and full collections, since scavenges
> > > also occur during incremental marking. The epoch is also process-wide,
> > > so different isolates do not reuse the same id.
> > >
> > > Change-Id: I8889bccce51e008374b4796445a50062bd87a45d
> > > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2565247
> > > Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
> > > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> > > Cr-Commit-Position: refs/heads/master@{#71521}
> >
> > Change-Id: Ib8f4bfdc01c459955eb6db63bb6e24a8aa068f09
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2567702
> > Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
> > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#71567}
>
> TBR=ulan@chromium.org,dinfuehr@chromium.org
>
> Change-Id: I09dcfabbad4ef1ad50e02a227282982cd7d87997
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2571122
> Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
> Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#71609}

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

Change-Id: I9dfd37f969ec0c5e5f278e6a82732995fd82e5d9
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2574002Reviewed-by: Sathya Gunasekaran  <gsathya@chromium.org>
Commit-Queue: Sathya Gunasekaran  <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71610}