In-place shrinking of descriptor arrays with non-live transitions.

src/objects-printer.cc

 // 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 261 matching lines @@
         case CALLBACKS:
           descs->GetCallbacksObject(i)->ShortPrint(out);
           PrintF(out, " (callback)\n");
           break;
         case MAP_TRANSITION:
           PrintF(out, "(map transition)\n");
           break;
         case CONSTANT_TRANSITION:
           PrintF(out, "(constant transition)\n");
           break;
-        case NULL_DESCRIPTOR:
-          PrintF(out, "(null descriptor)\n");
-          break;
         case NORMAL:  // only in slow mode
         case HANDLER:  // only in lookup results, not in descriptors
         case INTERCEPTOR:  // only in lookup results, not in descriptors
+        case NONEXISTENT:
           UNREACHABLE();
           break;
       }
     }
   } else {
     property_dictionary()->Print(out);
   }
 }
 
 
@@ skipping 723 matching lines @@
     desc.Print(out);
   }
   PrintF(out, "\n");
 }
 
 
 #endif  // OBJECT_PRINT
 
 
 } }  // namespace v8::internal