Get rid of assumptions about ".nexe" extension.

tests/fake_browser_ppapi/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')
 
 if 'TRUSTED_ENV' not in env:
   Return()
 
@@ skipping 55 matching lines @@
                                              'fake_url_response_info.cc',
                                              'fake_url_util.cc',
                                              'fake_window.cc',
                                              'main.cc',
                                              'test_scriptable.cc',
                                              'utility.cc'])
 
 target_nmf = 'basic_object.nmf';
 basic_object_nmf = env.File('${STAGING_DIR}/' + target_nmf)
 
-basic_object_target = env.File('$STAGING_DIR/ppapi_basic_object_%s.nexe' %
-                               env.get('TARGET_FULLARCH'))
+basic_object_target = env.File(
+    '$STAGING_DIR/ppapi_basic_object_${TARGET_FULLARCH}${PROGSUFFIX}')
 
 if trusted_env.Bit('mac'):
   plugin = trusted_env.File('${STAGING_DIR}/ppNaClPlugin')
 else:
   plugin = trusted_env.File('${STAGING_DIR}/${SHLIBPREFIX}'
                             'ppNaClPlugin${SHLIBSUFFIX}')
 sel_ldr = trusted_env.File('${STAGING_DIR}/${PROGPREFIX}sel_ldr${PROGSUFFIX}')
 log_file = env.MakeNaClLogOption('fake_browser_ppapi.out')
 
 test_env_vars = ['NACL_SEL_LDR=%s' % sel_ldr,
@@ skipping 10 matching lines @@
                         '"id=nacl_module;src=%s"' % target_nmf,
                         '${STAGING_DIR}'
                        ],
                        'medium',
                        osenv=test_env_vars,
                        extra_deps=[sel_ldr,
                                    basic_object_nmf,
                                    basic_object_target])
 
 env.AddNodeToTestSuite(node, ['medium_tests'], 'run_fake_browser_ppapi_test')