Add -a option to tools/build.py

tools/build.py

 #!/usr/bin/env python
 #
-# Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+# Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 #
 
 import optparse
 import os
 import shutil
 import subprocess
 import sys
 import utils
 
 HOST_OS = utils.GuessOS()
 HOST_CPUS = utils.GuessCpus()
 armcompilerlocation = '/opt/codesourcery/arm-2009q1'
 SCRIPT_DIR = os.path.dirname(sys.argv[0])
 DART_ROOT = os.path.realpath(os.path.join(SCRIPT_DIR, '..'))
 THIRD_PARTY_ROOT = os.path.join(DART_ROOT, 'third_party')
 
 def BuildOptions():
   result = optparse.OptionParser()
   result.add_option("-m", "--mode",
       help='Build variants (comma-separated).',
       metavar='[all,debug,release]',
       default='debug')
   result.add_option("-v", "--verbose",
       help='Verbose output.',
       default=False, action="store_true")
-  result.add_option("--arch",
+  result.add_option("-a", "--arch",
       help='Target architectures (comma-separated).',
       metavar='[all,ia32,x64,simarm,arm]',
       default=utils.GuessArchitecture())
   result.add_option("--os",
     help='Target OSs (comma-separated).',
     metavar='[all,host,android]',
     default='host')
   result.add_option("-j",
       help='The number of parallel jobs to run.',
       metavar=HOST_CPUS,
@@ skipping 278 matching lines @@
         process.wait()
         if process.returncode != 0:
           print "BUILD FAILED"
           return 1
 
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(Main())