Revert "[ptr-compr][x64] Temporarily enable pointer compression on x64"

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}

BUILD.gn

@@ -221,9 +221,8 @@ if (v8_enable_snapshot_native_code_counters == "") {
   v8_enable_snapshot_native_code_counters = v8_enable_debugging_features
 }
 if (v8_enable_pointer_compression == "") {
-  # TODO(v8:v7703): temporarily enable pointer compression on arm64 and on x64
-  v8_enable_pointer_compression =
-      v8_current_cpu == "arm64" || v8_current_cpu == "x64"
+  # TODO(v8:v7703): temporarily enable pointer compression on arm64
+  v8_enable_pointer_compression = v8_current_cpu == "arm64"
 }
 if (v8_enable_fast_torque == "") {
   v8_enable_fast_torque = v8_enable_fast_mksnapshot

infra/mb/mb_config.pyl

@@ -451,9 +451,9 @@
       'release_bot', 'x64', 'minimal_symbols'],
     'release_x64_pointer_compression': [
       'release_bot', 'x64', 'dcheck_always_on', 'v8_enable_slow_dchecks',
-      'v8_disable_pointer_compression'],
+      'v8_enable_pointer_compression'],
     'release_x64_pointer_compression_without_dchecks': [
-      'release_bot', 'x64', 'v8_disable_pointer_compression'],
+      'release_bot', 'x64', 'v8_enable_pointer_compression'],
     'release_x64_trybot': [
       'release_trybot', 'x64'],
     'release_x64_test_features_trybot': [
@@ -769,6 +769,10 @@
       'gn_args': 'v8_enable_slow_dchecks=true',
     },
 
+    'v8_enable_pointer_compression': {
+      'gn_args': 'v8_enable_pointer_compression=true',
+    },
+
     'v8_disable_pointer_compression': {
       'gn_args': 'v8_enable_pointer_compression=false',
     },