Prototype of mark-and-compact support for Harmony weak maps.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 15b0b3ee6c79fb8791ee454ef03f571313acf5ae..01289fb0b69facbfea84a0820f37bccceb1ef397 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -3804,6 +3804,12 @@ ACCESSORS(JSProxy, padding, Object, kPaddingOffset)
 
 
 ACCESSORS(JSWeakMap, table, ObjectHashTable, kTableOffset)
+ACCESSORS_GCSAFE(JSWeakMap, next, Object, kNextOffset)
+
+
+ObjectHashTable* JSWeakMap::unchecked_table() {
+  return reinterpret_cast<ObjectHashTable*>(READ_FIELD(this, kTableOffset));
+}
 
 
 Address Foreign::address() {
@@ -4409,6 +4415,11 @@ MaybeObject* ObjectHashTableShape::AsObject(JSObject* key) {
 }
 
 
+void ObjectHashTable::RemoveEntry(int entry) {
+  RemoveEntry(entry, GetHeap());
+}
+
+
 void Map::ClearCodeCache(Heap* heap) {
   // No write barrier is needed since empty_fixed_array is not in new space.
   // Please note this function is used during marking: