Use OrderedHashTables as the backing store of JSSet and JSMap

src/heap.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 56 matching lines @@
   V(Map, heap_number_map, HeapNumberMap)                                       \
   V(Map, native_context_map, NativeContextMap)                                 \
   V(Map, fixed_array_map, FixedArrayMap)                                       \
   V(Map, code_map, CodeMap)                                                    \
   V(Map, scope_info_map, ScopeInfoMap)                                         \
   V(Map, fixed_cow_array_map, FixedCOWArrayMap)                                \
   V(Map, fixed_double_array_map, FixedDoubleArrayMap)                          \
   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)             \
   V(ConstantPoolArray, empty_constant_pool_array, EmptyConstantPoolArray)      \
   V(Oddball, arguments_marker, ArgumentsMarker)                                \
   /* The roots above this line should be boring from a GC point of view.    */ \
   /* This means they are never in new space and never on a page that is     */ \
   /* being compacted.                                                       */ \
   V(FixedArray, number_string_cache, NumberStringCache)                        \
   V(Object, instanceof_cache_function, InstanceofCacheFunction)                \
@@ skipping 159 matching lines @@
   V(heap_number_map)                      \
   V(native_context_map)                   \
   V(fixed_array_map)                      \
   V(code_map)                             \
   V(scope_info_map)                       \
   V(fixed_cow_array_map)                  \
   V(fixed_double_array_map)               \
   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)               \
   V(empty_constant_pool_array)            \
   V(arguments_marker)                     \
   V(symbol_map)                           \
   V(sloppy_arguments_elements_map)        \
   V(function_context_map)                 \
   V(catch_context_map)                    \
   V(with_context_map)                     \
@@ skipping 2872 matching lines @@
   DisallowHeapAllocation no_allocation;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_