Introduce experimental natives that are enabled by a runtime flag.

src/SConscript

 # Copyright 2011 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 279 matching lines @@
 apinatives.js
 date.js
 regexp.js
 json.js
 liveedit-debugger.js
 mirror-debugger.js
 debug-debugger.js
 '''.split()
 
 
+EXPERIMENTAL_LIBRARY_FILES = '''
+proxy.js
+'''.split()
+
+
 def Abort(message):
   print message
   sys.exit(1)
 
 
 def ConfigureObjectFiles():
   env = Environment(tools=tools)
   env.Replace(**context.flags['v8'])
   context.ApplyEnvOverrides(env)
   env['BUILDERS']['JS2C'] = Builder(action=js2c.JS2C)
   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
   # compile it.
   library_files = [s for s in LIBRARY_FILES]
   library_files.append('macros.py')
-  libraries_src, libraries_empty_src = env.JS2C(['libraries.cc', 'libraries-empty.cc'], library_files, TYPE='CORE')
+  libraries_src = env.JS2C(['libraries.cc'], library_files, TYPE='CORE')
   libraries_obj = context.ConfigureObject(env, libraries_src, CPPPATH=['.'])
 
+  # Combine the experimental JavaScript library files into a C++ file
+  # and compile it.
+  experimental_library_files = [ s for s in EXPERIMENTAL_LIBRARY_FILES ]
+  experimental_library_files.append('macros.py')
+  experimental_libraries_src = env.JS2C(['experimental-libraries.cc'], experimental_library_files, TYPE='EXPERIMENTAL')
+  experimental_libraries_obj = context.ConfigureObject(env, experimental_libraries_src, CPPPATH=['.'])
+
   source_objs = context.ConfigureObject(env, source_files)
   non_snapshot_files = [source_objs]
 
   preparser_source_files = context.GetRelevantSources(PREPARSER_SOURCES)
   preparser_objs = context.ConfigureObject(env, preparser_source_files)
 
   # Create snapshot if necessary.  For cross compilation you should either
   # do without snapshots and take the performance hit or you should build a
   # host VM with the simulator=arm and snapshot=on options and then take the
   # resulting snapshot.cc file from obj/release and put it in the src
   # directory.  Then rebuild the VM with the cross compiler and specify
   # snapshot=nobuild on the scons command line.
   empty_snapshot_obj = context.ConfigureObject(env, 'snapshot-empty.cc')
   mksnapshot_env = env.Copy()
   mksnapshot_env.Replace(**context.flags['mksnapshot'])
   mksnapshot_src = 'mksnapshot.cc'
-  mksnapshot = mksnapshot_env.Program('mksnapshot', [mksnapshot_src, libraries_obj, non_snapshot_files, empty_snapshot_obj], PDB='mksnapshot.exe.pdb')
+  mksnapshot = mksnapshot_env.Program('mksnapshot', [mksnapshot_src, libraries_obj, experimental_libraries_obj,  non_snapshot_files, empty_snapshot_obj], PDB='mksnapshot.exe.pdb')
   if context.use_snapshot:
     if context.build_snapshot:
       snapshot_cc = env.Snapshot('snapshot.cc', mksnapshot, LOGFILE=File('snapshot.log').abspath)
     else:
       snapshot_cc = '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]
+  library_objs = [non_snapshot_files, libraries_obj, experimental_libraries_obj, snapshot_obj]
   return (library_objs, d8_objs, [mksnapshot], preparser_objs)
 
 
 (library_objs, d8_objs, mksnapshot, preparser_objs) = ConfigureObjectFiles()
 Return('library_objs d8_objs mksnapshot preparser_objs')