[heap][objects] Add V8_EXPORT_PRIVATE to TypedSlots and Smi::kZero.

Bug: chromium:701825, chromium:911856
Change-Id: Ic8d1ea35e0b21b481aab4c87037de6646ddfe450
Reviewed-on: https://chromium-review.googlesource.com/c/1372072
Commit-Queue: Max Moroz <mmoroz@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58188}

src/heap/slot-set.h

@@ -399,13 +399,13 @@ enum SlotType {
 // encoded (slot type, slot offset) pairs.
 // There is no duplicate detection and we do not expect many duplicates because
 // typed slots contain V8 internal pointers that are not directly exposed to JS.
-class TypedSlots {
+class V8_EXPORT_PRIVATE TypedSlots {
  public:
   static const int kMaxOffset = 1 << 29;
   TypedSlots() = default;
   virtual ~TypedSlots();
-  V8_EXPORT_PRIVATE void Insert(SlotType type, uint32_t offset);
-  V8_EXPORT_PRIVATE void Merge(TypedSlots* other);
+  void Insert(SlotType type, uint32_t offset);
+  void Merge(TypedSlots* other);
 
  protected:
   class OffsetField : public BitField<int, 0, 29> {};

src/objects/smi.h

@@ -98,7 +98,7 @@ class Smi : public ObjectPtr {
   // C++ does not allow us to have an object of type Smi within class Smi,
   // so the kZero value has type ObjectPtr. Consider it deprecated; new code
   // should use zero() instead.
-  static constexpr ObjectPtr kZero = ObjectPtr(0);
+  V8_EXPORT_PRIVATE static constexpr ObjectPtr kZero = ObjectPtr(0);
   // If you need something with type Smi, call zero() instead. Since it is
   // a constexpr, "calling" it is just as efficient as reading kZero.
   static inline constexpr Smi zero() { return Smi::FromInt(0); }