Revert of Add the concept of a V8 extras exports object

src/contexts.h

Index: src/contexts.h
diff --git a/src/contexts.h b/src/contexts.h
index 2aef4c381b00119fee6ad3efe14bbc593b1c3805..2d04da29b3bd1d2444c54bb76a01fb02314e9a66 100644
--- a/src/contexts.h
+++ b/src/contexts.h
@@ -185,8 +185,7 @@
   V(MAP_ITERATOR_MAP_INDEX, Map, map_iterator_map)                             \
   V(SET_ITERATOR_MAP_INDEX, Map, set_iterator_map)                             \
   V(ARRAY_VALUES_ITERATOR_INDEX, JSFunction, array_values_iterator)            \
-  V(SCRIPT_CONTEXT_TABLE_INDEX, ScriptContextTable, script_context_table)      \
-  V(EXTRAS_EXPORTS_OBJECT_INDEX, JSObject, extras_exports_object)
+  V(SCRIPT_CONTEXT_TABLE_INDEX, ScriptContextTable, script_context_table)
 
 
 // A table of all script contexts. Every loaded top-level script with top-level
@@ -423,7 +422,6 @@
     SCRIPT_CONTEXT_TABLE_INDEX,
     MAP_CACHE_INDEX,
     TO_LENGTH_FUN_INDEX,
-    EXTRAS_EXPORTS_OBJECT_INDEX,
 
     // Properties from here are treated as weak references by the full GC.
     // Scavenge treats them as strong references.