Use OrderedHashTables as the backing store of JSSet and JSMap

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 978704ac54286aff224e370390121e305cd45100..f72b3821f5f8023734bc179322e7ee4827c0b2e7 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -920,6 +920,23 @@ bool Object::IsObjectHashTable() {
 }
 
 
+bool Object::IsOrderedHashTable() {
+  return IsHeapObject() &&
+      HeapObject::cast(this)->map() ==
+      HeapObject::cast(this)->GetHeap()->ordered_hash_table_map();
+}
+
+
+bool Object::IsOrderedHashSet() {
+  return IsOrderedHashTable();
+}
+
+
+bool Object::IsOrderedHashMap() {
+  return IsOrderedHashTable();
+}
+
+
 bool Object::IsPrimitive() {
   return IsOddball() || IsNumber() || IsString();
 }
@@ -2963,6 +2980,8 @@ CAST_ACCESSOR(ExternalFloat64Array)
 CAST_ACCESSOR(ExternalUint8ClampedArray)
 CAST_ACCESSOR(Struct)
 CAST_ACCESSOR(AccessorInfo)
+CAST_ACCESSOR(OrderedHashMap)
+CAST_ACCESSOR(OrderedHashSet)
 
 template <class Traits>
 FixedTypedArray<Traits>* FixedTypedArray<Traits>::cast(Object* object) {
@@ -6588,28 +6607,22 @@ MaybeObject* NameDictionaryShape::AsObject(Heap* heap, Name* key) {
 }
 
 
-template <int entrysize>
-bool ObjectHashTableShape<entrysize>::IsMatch(Object* key, Object* other) {
+bool ObjectHashTableShape::IsMatch(Object* key, Object* other) {
   return key->SameValue(other);
 }
 
 
-template <int entrysize>
-uint32_t ObjectHashTableShape<entrysize>::Hash(Object* key) {
+uint32_t ObjectHashTableShape::Hash(Object* key) {
   return Smi::cast(key->GetHash())->value();
 }
 
 
-template <int entrysize>
-uint32_t ObjectHashTableShape<entrysize>::HashForObject(Object* key,
-                                                        Object* other) {
+uint32_t ObjectHashTableShape::HashForObject(Object* key, Object* other) {
   return Smi::cast(other->GetHash())->value();
 }
 
 
-template <int entrysize>
-MaybeObject* ObjectHashTableShape<entrysize>::AsObject(Heap* heap,
-                                                       Object* key) {
+MaybeObject* ObjectHashTableShape::AsObject(Heap* heap, Object* key) {
   return key;
 }