Get rid of the NONEXISTENT PropertyType

src/property-details.h

Index: src/property-details.h
diff --git a/src/property-details.h b/src/property-details.h
index 7eb2e4ea9da8f660183f185bc759e01248813fa4..960c46c4f79a91580defd124b9c71d8def94da36 100644
--- a/src/property-details.h
+++ b/src/property-details.h
@@ -46,16 +46,14 @@ class TypeInfo;
 // A copy of this is in mirror-debugger.js.
 enum PropertyType {
   // Only in slow mode.
-  NORMAL                    = 0,
+  NORMAL = 0,
   // Only in fast mode.
-  FIELD                     = 1,
-  CONSTANT                  = 2,
-  CALLBACKS                 = 3,
+  FIELD = 1,
+  CONSTANT = 2,
+  CALLBACKS = 3,
   // Only in lookup results, not in descriptors.
-  HANDLER                   = 4,
-  INTERCEPTOR               = 5,
-  // Only used as a marker in LookupResult.
-  NONEXISTENT               = 6
+  HANDLER = 4,
+  INTERCEPTOR = 5
 };