This reverts commit 4f051fd5.

Reason for revert: Fails with custom snapshot on GC stress - https://ci.chromium.org/p/v8/builders/ci/V8%20Linux64%20GC%20Stress%20-%20custom%20snapshot/24855

Original change's description:
> Reland "[ptr-compr][x64] Temporarily enable pointer compression on x64"
> 
> This is a reland of 589d1a6b
> 
> Relanding after fixing TSan and UBSan issues.
> 
> Original change's description:
> > [ptr-compr][x64] Temporarily enable pointer compression on x64
> >
> > ... and make sure that the x64 ptr-compr bots proceed testing V8 without
> > pointer compression in order to keep testing the full pointer mode.
> >
> > Bug: v8:7703
> > Change-Id: Iee725deda813425a6f0722948b54976154f50909
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1497139
> > Reviewed-by: Michael Hablich <hablich@chromium.org>
> > Reviewed-by: Michael Achenbach <machenbach@chromium.org>
> > Commit-Queue: Michael Achenbach <machenbach@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#60230}
> 
> Cq-Include-Trybots: luci.v8.try:v8_linux64_ubsan_rel_ng,v8_linux64_tsan_rel
> Bug: v8:7703
> Change-Id: Ied4e7bacf99c9d63e0459613fec522273f595de8
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1523327
> Commit-Queue: Igor Sheludko <ishell@chromium.org>
> Auto-Submit: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Michael Achenbach <machenbach@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#60339}

TBR=machenbach@chromium.org,hablich@chromium.org,leszeks@chromium.org,ishell@chromium.org,verwaest@chromium.org

Change-Id: Ia06829e9dfdf09501ceebc0eef175d3261969d1f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7703
Cq-Include-Trybots: luci.v8.try:v8_linux64_ubsan_rel_ng, v8_linux64_tsan_rel
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1531120Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
Commit-Queue: Deepti Gandluri <gdeepti@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60340}