Fix issue 571: display descriptive names for code objects from snapshot.

src/SConscript

 # Copyright 2008 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 217 matching lines @@
 def Abort(message):
   print message
   sys.exit(1)
 
 
 def ConfigureObjectFiles():
   env = Environment()
   env.Replace(**context.flags['v8'])
   context.ApplyEnvOverrides(env)
   env['BUILDERS']['JS2C'] = Builder(action=js2c.JS2C)
-  env['BUILDERS']['Snapshot'] = Builder(action='$SOURCE $TARGET --logfile "$LOGFILE"')
+  env['BUILDERS']['Snapshot'] = Builder(action='$SOURCE $TARGET --logfile "$LOGFILE" --log-snapshot-positions')
 
   # Build the standard platform-independent source files.
   source_files = context.GetRelevantSources(SOURCES)
 
   d8_files = context.GetRelevantSources(D8_FILES)
   d8_js = env.JS2C('d8-js.cc', 'd8.js', TYPE='D8')
   d8_js_obj = context.ConfigureObject(env, d8_js, CPPPATH=['.'])
   d8_objs = [context.ConfigureObject(env, [d8_files]), d8_js_obj]
 
   # Combine the JavaScript library files into a single C++ file and
@@ skipping 25 matching lines @@
       snapshot_cc = Command('snapshot.cc', [], [])
     snapshot_obj = context.ConfigureObject(env, snapshot_cc, CPPPATH=['.'])
   else:
     snapshot_obj = empty_snapshot_obj
   library_objs = [non_snapshot_files, libraries_obj, snapshot_obj]
   return (library_objs, d8_objs, [mksnapshot])
 
 
 (library_objs, d8_objs, mksnapshot) = ConfigureObjectFiles()
 Return('library_objs d8_objs mksnapshot')