[ptr-compr][x64] Enable pointer compression on x64

Chromium LSAN bot failures are fixed on Chromium side:
https://chromium-review.googlesource.com/c/chromium/src/+/1926472

Bug: v8:7703
Change-Id: I830b747ca2f2f1b3c5adf31b42b3b8112c5d4457
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,linux_chromium_asan_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1925149Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65136}

BUILD.gn

@@ -230,8 +230,9 @@ 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
-  v8_enable_pointer_compression = v8_current_cpu == "arm64"
+  # TODO(v8:v7703): temporarily enable pointer compression on arm64 and on x64
+  v8_enable_pointer_compression =
+      v8_current_cpu == "arm64" || v8_current_cpu == "x64"
 }
 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_enable_pointer_compression'],
+      'v8_disable_pointer_compression'],
     'release_x64_pointer_compression_without_dchecks': [
-      'release_bot', 'x64', 'v8_enable_pointer_compression'],
+      'release_bot', 'x64', 'v8_disable_pointer_compression'],
     'release_x64_trybot': [
       'release_trybot', 'x64'],
     'release_x64_test_features_trybot': [
@@ -769,10 +769,6 @@
       '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',
     },