This reverts commit 0e31eb9e.

Reason for revert: Need to land:
https://chromium-review.googlesource.com/c/v8/v8/+/1918258

Original change's description:
> [ptr-compr][x64] Temporarily enable pointer compression on x64
>
> Bug: v8:7703
> Change-Id: I50bb3d336d48f0fe176d2bae3536f049e2bf5cf8
> Cq-Include-Trybots: luci.v8.try:v8_linux64_ubsan_rel_ng,v8_linux64_tsan_rel
> Cq-Include-Trybots: luci.v8.try:v8_linux64_cfi_rel_ng
> Cq-Include-Trybots: luci.chromium.try:fuchsia_x64,linux-rel,mac-rel
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1918253
> Commit-Queue: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Reviewed-by: Michael Achenbach <machenbach@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#64994}

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

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: v8:7703
Change-Id: If80aeee94844f0d855f9d6d02cabf9d9f979779d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1921787
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65000}