Ensure slow properties for simple {__proto__:null} literals.

src/objects.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 #include <memory>
 
@@ skipping 2809 matching lines @@
   inline Object** RawFieldOfElementAt(int index);
 
   DECLARE_CAST(FixedArray)
 
   // Maximal allowed size, in bytes, of a single FixedArray.
   // Prevents overflowing size computations, as well as extreme memory
   // consumption.
   static const int kMaxSize = 128 * MB * kPointerSize;
   // Maximally allowed length of a FixedArray.
   static const int kMaxLength = (kMaxSize - kHeaderSize) / kPointerSize;
+  // Maximally allowed length for regular (non large object space) object.
+  STATIC_ASSERT(kMaxRegularHeapObjectSize < kMaxSize);
+  static const int kMaxRegularLength =
+      (kMaxRegularHeapObjectSize - kHeaderSize) / kPointerSize;
 
   // Dispatched behavior.
   DECLARE_PRINTER(FixedArray)
   DECLARE_VERIFIER(FixedArray)
 #ifdef DEBUG
   // Checks if two FixedArrays have identical contents.
   bool IsEqualTo(FixedArray* other);
 #endif
 
   typedef FlexibleBodyDescriptor<kHeaderSize> BodyDescriptor;
@@ skipping 1982 matching lines @@
 
   // Returns a non-deprecated version of the input. This method may deprecate
   // existing maps along the way if encodings conflict. Not for use while
   // gathering type feedback. Use TryUpdate in those cases instead.
   static Handle<Map> Update(Handle<Map> map);
 
   static inline Handle<Map> CopyInitialMap(Handle<Map> map);
   static Handle<Map> CopyInitialMap(Handle<Map> map, int instance_size,
                                     int in_object_properties,
                                     int unused_property_fields);
+  static Handle<Map> CopyInitialMapNormalized(
+      Handle<Map> map,
+      PropertyNormalizationMode mode = CLEAR_INOBJECT_PROPERTIES);
   static Handle<Map> CopyDropDescriptors(Handle<Map> map);
   static Handle<Map> CopyInsertDescriptor(Handle<Map> map,
                                           Descriptor* descriptor,
                                           TransitionFlag flag);
 
   static Handle<Object> WrapFieldType(Handle<FieldType> type);
   static FieldType* UnwrapFieldType(Object* wrapped_type);
 
   MUST_USE_RESULT static MaybeHandle<Map> CopyWithField(
       Handle<Map> map, Handle<Name> name, Handle<FieldType> type,
@@ skipping 5429 matching lines @@
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #include "src/objects/object-macros-undef.h"
 
 #endif  // V8_OBJECTS_H_