Revert "[compiler] Perform MapRef's SupportsFastArray methods concurrently"

This reverts commit ebd9dcda.

Reason for revert: https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Linux%20gcc/11378/overview

Original change's description:
> [compiler] Perform MapRef's SupportsFastArray methods concurrently
>
> We are safe to go through the native_contexts_list_ since we do it
> through IsAnyInitialArrayPrototype which disallows the GC. Furthermore,
> we read that list with an acquire load which guarantees that the fields
> have been initialized.
>
> Bug: v8:7790
> Change-Id: I778d51f4ead44e472f842693a7e9ff577d6acfe3
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2826541
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#74086}

Bug: v8:7790
Change-Id: I4ef0056fb5ab9bd037375f67ec704f842e003283
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2843360
Auto-Submit: Sathya Gunasekaran  <gsathya@chromium.org>
Reviewed-by: Sathya Gunasekaran  <gsathya@chromium.org>
Commit-Queue: Sathya Gunasekaran  <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74087}

src/compiler/heap-refs.cc

@@ -2880,14 +2880,14 @@ bool MapRef::HasOnlyStablePrototypesWithFastElements(
 }
 
 bool MapRef::supports_fast_array_iteration() const {
-  if (data_->should_access_heap() || FLAG_turbo_direct_heap_access) {
+  if (data_->should_access_heap()) {
     return SupportsFastArrayIteration(broker()->isolate(), object());
   }
   return data()->AsMap()->supports_fast_array_iteration();
 }
 
 bool MapRef::supports_fast_array_resize() const {
-  if (data_->should_access_heap() || FLAG_turbo_direct_heap_access) {
+  if (data_->should_access_heap()) {
     return SupportsFastArrayResize(broker()->isolate(), object());
   }
   return data()->AsMap()->supports_fast_array_resize();

src/heap/heap.h

@@ -569,12 +569,9 @@ class Heap {
   V8_EXPORT_PRIVATE int NotifyContextDisposed(bool dependant_context);
 
   void set_native_contexts_list(Object object) {
-    native_contexts_list_.store(object, std::memory_order_release);
-  }
-
-  Object native_contexts_list() const {
-    return native_contexts_list_.load(std::memory_order_acquire);
+    native_contexts_list_ = object;
   }
+  Object native_contexts_list() const { return native_contexts_list_; }
 
   void set_allocation_sites_list(Object object) {
     allocation_sites_list_ = object;
@@ -2203,7 +2200,7 @@ class Heap {
 
   // Weak list heads, threaded through the objects.
   // List heads are initialized lazily and contain the undefined_value at start.
-  std::atomic<Object> native_contexts_list_;
+  Object native_contexts_list_;
   Object allocation_sites_list_;
   Object dirty_js_finalization_registries_list_;
   // Weak list tails.