[compiler] Make AccessorAccessInfoHelper read of module cell relaxed

... as the main thread might change its contents.

Bug: v8:12174, v8:7790
Change-Id: I66b2cafc7ddc9b387223693595a9d810b272d7b9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3141586Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/main@{#76685}

src/compiler/access-info.cc

@@ -544,7 +544,7 @@ PropertyAccessInfo AccessorAccessInfoHelper(
     Handle<Cell> cell = broker->CanonicalPersistentHandle(
         Cell::cast(module_namespace->module().exports().Lookup(
             isolate, name.object(), Smi::ToInt(name.object()->GetHash()))));
-    if (cell->value().IsTheHole(isolate)) {
+    if (cell->value(kRelaxedLoad).IsTheHole(isolate)) {
       // This module has not been fully initialized yet.
       return PropertyAccessInfo::Invalid(zone);
     }

src/objects/cell-inl.h

@@ -20,6 +20,10 @@ namespace internal {
 
 TQ_OBJECT_CONSTRUCTORS_IMPL(Cell)
 
+DEF_RELAXED_GETTER(Cell, value, Object) {
+  return TaggedField<Object, kValueOffset>::Relaxed_Load(cage_base, *this);
+}
+
 }  // namespace internal
 }  // namespace v8
 

src/objects/cell.h

@@ -19,6 +19,9 @@ class Cell : public TorqueGeneratedCell<Cell, HeapObject> {
  public:
   inline Address ValueAddress() { return address() + kValueOffset; }
 
+  using TorqueGeneratedCell::value;
+  DECL_RELAXED_GETTER(value, Object)
+
   using BodyDescriptor = FixedBodyDescriptor<kValueOffset, kSize, kSize>;
 
   TQ_OBJECT_CONSTRUCTORS(Cell)