Revert "[heap] Ensure all old-to-shared slots are recorded"

This reverts commit c3a5c5b1.

Reason for revert: https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Linux64%20-%20shared/21941/overview

Original change's description:
> [heap] Ensure all old-to-shared slots are recorded
>
> This CL adds verification of the old-to-shared remembered set to
> --verify-heap. During shared GCs client heaps will be scanned for
> references into the shared heap, this CL will CHECK that every found
> slot is contained in the old-to-shared remembered set. After this
> gets a bit more stable, the full heap iteration can be dropped and we
> can fully rely on the remembered set instead.
>
> Bug: v8:11708
> Change-Id: I0b5c4edfe3271306e4e7af7394472534113e1953
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3792605
> Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
> Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#82578}

Bug: v8:11708
Change-Id: I26553d3b06d0e257a3425eeb884ccce57f026bde
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3841567
Owners-Override: Nico Hartmann <nicohartmann@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Auto-Submit: Nico Hartmann <nicohartmann@chromium.org>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#82580}

src/heap/heap-inl.h

@@ -283,13 +283,6 @@ bool Heap::InYoungGeneration(HeapObject heap_object) {
   return result;
 }
 
-// static
-bool Heap::InSharedWritableHeap(MaybeObject object) {
-  HeapObject heap_object;
-  return object->GetHeapObject(&heap_object) &&
-         heap_object.InSharedWritableHeap();
-}
-
 // static
 bool Heap::InFromPage(Object object) {
   DCHECK(!HasWeakHeapObjectTag(object));

src/heap/heap.cc

@@ -4691,18 +4691,6 @@ class OldToNewSlotVerifyingVisitor : public SlotVerifyingVisitor {
   EphemeronRememberedSet* ephemeron_remembered_set_;
 };
 
-class OldToSharedSlotVerifyingVisitor : public SlotVerifyingVisitor {
- public:
-  OldToSharedSlotVerifyingVisitor(Isolate* isolate, std::set<Address>* untyped,
-                                  std::set<std::pair<SlotType, Address>>* typed)
-      : SlotVerifyingVisitor(isolate, untyped, typed) {}
-
-  bool ShouldHaveBeenRecorded(HeapObject host, MaybeObject target) override {
-    return target->IsStrongOrWeak() && Heap::InSharedWritableHeap(target) &&
-           !Heap::InYoungGeneration(host) && !host.InSharedWritableHeap();
-  }
-};
-
 template <RememberedSetType direction>
 void CollectSlots(MemoryChunk* chunk, Address start, Address end,
                   std::set<Address>* untyped,
@@ -4734,31 +4722,14 @@ void Heap::VerifyRememberedSetFor(HeapObject object) {
   PtrComprCageBase cage_base(isolate());
   Address start = object.address();
   Address end = start + object.Size(cage_base);
-
+  std::set<Address> old_to_new;
+  std::set<std::pair<SlotType, Address>> typed_old_to_new;
   if (!InYoungGeneration(object)) {
-    std::set<Address> old_to_new;
-    std::set<std::pair<SlotType, Address>> typed_old_to_new;
     CollectSlots<OLD_TO_NEW>(chunk, start, end, &old_to_new, &typed_old_to_new);
-    OldToNewSlotVerifyingVisitor old_to_new_visitor(
-        isolate(), &old_to_new, &typed_old_to_new,
-        &this->ephemeron_remembered_set_);
-    object.IterateBody(cage_base, &old_to_new_visitor);
-
-    std::set<Address> old_to_shared;
-    std::set<std::pair<SlotType, Address>> typed_old_to_shared;
-    CollectSlots<OLD_TO_SHARED>(chunk, start, end, &old_to_new,
-                                &typed_old_to_new);
-    OldToSharedSlotVerifyingVisitor old_to_shared_visitor(
-        isolate(), &old_to_shared, &typed_old_to_shared);
-    object.IterateBody(cage_base, &old_to_shared_visitor);
-
-    if (chunk->InSharedHeap()) {
-      CHECK_NULL(chunk->slot_set<OLD_TO_NEW>());
-      CHECK_NULL(chunk->typed_slot_set<OLD_TO_NEW>());
-
-      CHECK_NULL(chunk->slot_set<OLD_TO_OLD>());
-      CHECK_NULL(chunk->typed_slot_set<OLD_TO_OLD>());
-    }
+    OldToNewSlotVerifyingVisitor visitor(isolate(), &old_to_new,
+                                         &typed_old_to_new,
+                                         &this->ephemeron_remembered_set_);
+    object.IterateBody(cage_base, &visitor);
   }
   // TODO(v8:11797): Add old to old slot set verification once all weak objects
   // have their own instance types and slots are recorded for all weak fields.

src/heap/heap.h

@@ -1262,9 +1262,6 @@ class Heap {
   // spaces.
   V8_EXPORT_PRIVATE bool ContainsCode(HeapObject value) const;
 
-  // Checks whether object resides in the non-read-only shared heap.
-  static inline bool InSharedWritableHeap(MaybeObject object);
-
   // Checks whether an address/object is in the non-read-only heap (including
   // auxiliary area and unused area). Use IsValidHeapObject if checking both
   // heaps is required.

src/heap/mark-compact.cc

@@ -1369,16 +1369,9 @@ class MarkCompactCollector::SharedHeapObjectVisitor final
     DCHECK(!host.InSharedHeap());
     if (!object.IsHeapObject()) return;
     HeapObject heap_object = HeapObject::cast(object);
-    if (!heap_object.InSharedWritableHeap()) return;
-    DCHECK(heap_object.InSharedWritableHeap());
-    MemoryChunk* host_chunk = MemoryChunk::FromHeapObject(host);
-    if (host_chunk->InYoungGeneration()) {
-      RememberedSet<OLD_TO_SHARED>::Insert<AccessMode::NON_ATOMIC>(
-          host_chunk, slot.address());
-    } else {
-      CHECK(RememberedSet<OLD_TO_SHARED>::Contains(host_chunk, slot.address()));
-    }
-
+    if (!heap_object.InSharedHeap()) return;
+    RememberedSet<OLD_TO_SHARED>::Insert<AccessMode::NON_ATOMIC>(
+        MemoryChunk::FromHeapObject(host), slot.address());
     collector_->MarkRootObject(Root::kClientHeap, heap_object);
   }