Pass the pointer of owning object in GCHermesValueBase::set() (#1512)

Summary:
Pull Request resolved: #1512

This variant will be used by write barriers that support large
allocation in following diffs.

Differential Revision: D62196480

Author: lavenzg

include/hermes/VM/HermesValue-inline.h

@@ -61,6 +61,23 @@ inline void GCHermesValueBase<HVType>::set(HVType hv, GC &gc) {
   HVType::setNoBarrier(hv);
 }
 
+template <typename HVType>
+template <typename NeedsBarriers>
+inline void
+GCHermesValueBase<HVType>::set(HVType hv, GC &gc, const GCCell *owningObj) {
+  if (hv.isPointer()) {
+    HERMES_SLOW_ASSERT(
+        gc.validPointer(hv.getPointer(gc.getPointerBase())) &&
+        "Setting an invalid pointer into a GCHermesValue");
+  }
+  assert(NeedsBarriers::value || !gc.needsWriteBarrier(this, hv));
+  (void)owningObj;
+  if constexpr (NeedsBarriers::value) {
+    gc.writeBarrier(this, hv);
+  }
+  HVType::setNoBarrier(hv);
+}
+
 template <typename HVType>
 void GCHermesValueBase<HVType>::setNonPtr(HVType hv, GC &gc) {
   assert(!hv.isPointer());

include/hermes/VM/HermesValue.h

@@ -530,11 +530,19 @@ class GCHermesValueBase final : public HVType {
   GCHermesValueBase(HVType hv, GC &gc, std::nullptr_t);
   GCHermesValueBase(const HVType &) = delete;
 
-  /// The HermesValue \p hv may be an object pointer.  Assign the
-  /// value, and perform any necessary write barriers.
+  /// The HermesValue \p hv may be an object pointer. Assign the value, and
+  /// perform any necessary write barriers. This must not be used if it lives in
+  /// an object that supports large allocation.
   template <typename NeedsBarriers = std::true_type>
   inline void set(HVType hv, GC &gc);
 
+  /// The HermesValue \p hv may be an object pointer. Assign the value, and
+  /// perform any necessary write barriers. \p owningObj is the object that
+  /// contains this GCHermesValueBase, and it may support large allocation.
+  /// for which the object pointer is needed by writer barriers.
+  template <typename NeedsBarriers = std::true_type>
+  inline void set(HVType hv, GC &gc, const GCCell *owningObj);
+
   /// The HermesValue \p hv must not be an object pointer.  Assign the
   /// value.
   /// Some GCs still need to do a write barrier though, so pass a GC parameter.