Use OrderedHashTables as the backing store of JSSet and JSMap

src/heap.h

Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index b8110920b22de919ee7968ec22e7461d45c8e6d4..b0872e54c973a4193864b6891e6475b24dc9bf5a 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -74,6 +74,7 @@ namespace internal {
   V(Map, constant_pool_array_map, ConstantPoolArrayMap)                        \
   V(Object, no_interceptor_result_sentinel, NoInterceptorResultSentinel)       \
   V(Map, hash_table_map, HashTableMap)                                         \
+  V(Map, ordered_hash_table_map, OrderedHashTableMap)                          \
   V(FixedArray, empty_fixed_array, EmptyFixedArray)                            \
   V(ByteArray, empty_byte_array, EmptyByteArray)                               \
   V(DescriptorArray, empty_descriptor_array, EmptyDescriptorArray)             \
@@ -253,6 +254,7 @@ namespace internal {
   V(constant_pool_array_map)              \
   V(no_interceptor_result_sentinel)       \
   V(hash_table_map)                       \
+  V(ordered_hash_table_map)               \
   V(empty_fixed_array)                    \
   V(empty_byte_array)                     \
   V(empty_descriptor_array)               \