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

src/interpreter/bytecode-flags.h

 // Copyright 2016 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_INTERPRETER_BYTECODE_FLAGS_H_
 #define V8_INTERPRETER_BYTECODE_FLAGS_H_
 
 #include "src/utils.h"
 
 namespace v8 {
 namespace internal {
 
 // Forward declarations.
 class Literal;
 class AstStringConstants;
 
 namespace interpreter {
 
 class CreateArrayLiteralFlags {
  public:
-  class FlagsBits : public BitField8<int, 0, 3> {};
+  class FlagsBits : public BitField8<int, 0, 4> {};
   class FastShallowCloneBit : public BitField8<bool, FlagsBits::kNext, 1> {};
 
   static uint8_t Encode(bool use_fast_shallow_clone, int runtime_flags);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(CreateArrayLiteralFlags);
 };
 
 class CreateObjectLiteralFlags {
  public:
-  class FlagsBits : public BitField8<int, 0, 3> {};
+  class FlagsBits : public BitField8<int, 0, 4> {};
   class FastClonePropertiesCountBits
       : public BitField8<int, FlagsBits::kNext, 3> {};
 
   static uint8_t Encode(bool fast_clone_supported, int properties_count,
                         int runtime_flags);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(CreateObjectLiteralFlags);
 };
 
@@ skipping 46 matching lines @@
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(SuspendGeneratorBytecodeFlags);
 };
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_BYTECODE_FLAGS_H_