Correctly propagate toolchain setting in SConstruct.

SConstruct

 # 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 1407 matching lines @@
   )
   context.cctest_targets.append(cctest_program)
 
   preparser_env = env.Copy()
   preparser_env.Replace(**context.flags['preparser'])
   preparser_env.Prepend(LIBS=[preparser_library_name])
   context.ApplyEnvOverrides(preparser_env)
   preparser_object = preparser_env.SConscript(
     join('preparser', 'SConscript'),
     build_dir=join('obj', 'preparser', target_id),
-    exports='context',
+    exports='context tools',
     duplicate=False
   )
   preparser_name = join('obj', 'preparser', target_id, 'preparser')
   preparser_program = preparser_env.Program(preparser_name, preparser_object);
   preparser_env.Depends(preparser_program, preparser_library)
   context.preparser_targets.append(preparser_program)
 
   return context
 
 
@@ skipping 44 matching lines @@
 # version of scons.  Also, there's a bug in some revisions that
 # doesn't allow this flag to be set, so we swallow any exceptions.
 # Lovely.
 try:
   SetOption('warn', 'no-deprecated')
 except:
   pass
 
 
 Build()