Get rid of assumptions about ".nexe" extension.

tests/imc_shm_mmap/nacl.scons

 # -*- python -*-
 # Copyright (c) 2011 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.
 
 Import('env')
 
-imc_shm_mmap_test_nexe_name = ('imc_shm_mmap_test_%s.nexe' %
+imc_shm_mmap_test_nexe_name = ('imc_shm_mmap_test_%s' %
                                env.get('TARGET_FULLARCH'))
 imc_shm_mmap_test_nexe = env.ComponentProgram(imc_shm_mmap_test_nexe_name,
                                               'imc_shm_mmap_test.c',
                                               EXTRA_LIBS=[
                                                   '${NON_PPAPI_BROWSER_LIBS}',
                                                   'testrunner',
                                                   'srpc',
                                                   'imc_syscalls',
                                                   'platform',
                                                   'gio',
                                                   'pthread',
                                                   ])
 env.Publish(imc_shm_mmap_test_nexe_name, 'run', ['imc_shm_mmap_test.nmf'])
 
 node = env.CommandSelLdrTestNacl(
     'imc_shm_mmap_test.out',
-    command=[imc_shm_mmap_test_nexe],
+    imc_shm_mmap_test_nexe,
     # We need to set this because the test needs to behave
     # differently in the plugin, but the plugin does not provide a
     # way to distinguish itself.  TODO(mseaborn): Fix that.
     # See http://code.google.com/p/nativeclient/issues/detail?id=889
     sel_ldr_flags=['-E', 'NACL_SRPC_STANDALONE=1'])
 env.AddNodeToTestSuite(node, ['small_tests'], 'run_imc_shm_mmap_test')