[Arguments] Introduce a new backing store for non-strict arguments objects.

src/objects.h

 // Copyright 2010 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 1314 matching lines @@
     NORMAL_DELETION,
     STRICT_DELETION,
     FORCE_DELETION
   };
 
   enum ElementsKind {
     // The only "fast" kind.
     FAST_ELEMENTS,
     // All the kinds below are "slow".
     DICTIONARY_ELEMENTS,
+    NON_STRICT_ARGUMENTS_ELEMENTS,
     EXTERNAL_BYTE_ELEMENTS,
     EXTERNAL_UNSIGNED_BYTE_ELEMENTS,
     EXTERNAL_SHORT_ELEMENTS,
     EXTERNAL_UNSIGNED_SHORT_ELEMENTS,
     EXTERNAL_INT_ELEMENTS,
     EXTERNAL_UNSIGNED_INT_ELEMENTS,
     EXTERNAL_FLOAT_ELEMENTS,
     EXTERNAL_PIXEL_ELEMENTS
   };
 
@@ skipping 5299 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_