Ignore buildtools directory in presubmit.py checks

tools/presubmit.py

 #!/usr/bin/env python
 #
 # Copyright 2012 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
@@ skipping 183 matching lines @@
   def Run(self, path):
     all_files = []
     for file in self.GetPathsToSearch():
       all_files += self.FindFilesIn(join(path, file))
     if not self.ProcessFiles(all_files, path):
       return False
     return True
 
   def IgnoreDir(self, name):
     return (name.startswith('.') or
-            name in ('data', 'kraken', 'octane', 'sunspider'))
+            name in ('buildtools', 'data', 'kraken', 'octane', 'sunspider'))
 
   def IgnoreFile(self, name):
     return name.startswith('.')
 
   def FindFilesIn(self, path):
     result = []
     for (root, dirs, files) in os.walk(path):
       for ignored in [x for x in dirs if self.IgnoreDir(x)]:
         dirs.remove(ignored)
       for file in files:
@@ skipping 229 matching lines @@
   success = SourceProcessor().Run(workspace) and success
   success = CheckGeneratedRuntimeTests(workspace) and success
   if success:
     return 0
   else:
     return 1
 
 
 if __name__ == '__main__':
   sys.exit(Main())