NaCl test script: get the run.py translation arch from the environment

test/builtins/Unit/nacltest.py

 #!/usr/bin/env python
 # Copyright (c) 2015 The Native Client Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # This script runs the tests for compiler_rt. It is meant to run on a
 # fully-constructed toolchain (as opposed to being run during the compiler-rt
 # build process) because the tests need libc/libnacl to link.
 
 import os
@@ skipping 46 matching lines @@
   tests = get_tests(functions, test_src_dir)
   run_py = find_run_py()
   failures = 0
   workdir = tempfile.mkdtemp()
 
   for test in tests:
     flags = ['-lm']
     exe_suffix = '.pexe' if 'pnacl-clang' in cc else '.nexe'
     nexe = os.path.join(workdir, os.path.basename(test + exe_suffix))
     build_cmd = [cc, '-I' + inc_dir, '-o', nexe, test] + flags
-    run_cmd = [run_py, nexe]
+    run_cmd = [run_py, '-arch', 'env', nexe]
     try:
       print ' '.join(build_cmd)
       subprocess.check_call(build_cmd)
       print ' '.join(run_cmd)
       subprocess.check_call(run_cmd)
     except subprocess.CalledProcessError, e:
       print '[  FAILED  ]:', test
       print e
       failures += 1
 
   shutil.rmtree(workdir)
   return failures
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv))