Get rid of assumptions about ".nexe" extension.

tests/ppapi_ppb_scrollbar/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')
 
 env.Prepend(CPPDEFINES=['XP_UNIX'])
 
-nexe = 'ppapi_ppb_scrollbar_%s.nexe' % env.get('TARGET_FULLARCH')
-env.Alias('ppapi_ppb_scrollbar.nexe', [ '$STAGING_DIR/%s' % nexe ])
+nexe = 'ppapi_ppb_scrollbar_${TARGET_FULLARCH}'
+env.Alias('ppapi_ppb_scrollbar${PROGSUFFIX}',
+          ['$STAGING_DIR/%s${PROGSUFFIX}' % nexe])
 
 ppapi_ppb_scrollbar_nexe = env.ComponentProgram(
     nexe,
     [ 'ppapi_ppb_scrollbar.cc' ],
     EXTRA_LIBS=['${PPAPI_LIBS}',
                 'ppapi_test_lib',
                 'pthread',
                 'platform',
                 'gio'])
 
 dest_copy = env.Replicate('$STAGING_DIR',
                           [ 'ppapi_ppb_scrollbar.html',
                             'ppapi_ppb_scrollbar.nmf',
                             env.File('${SCONSTRUCT_DIR}/tools/browser_tester/'
                                      'browserdata/nacltest.js') ]
                           )
 env.Depends(nexe, dest_copy)
 
 node = env.PPAPIBrowserTester('ppapi_ppb_scrollbar_browser_test.out',
                               url='ppapi_ppb_scrollbar.html',
                               files=[ ppapi_ppb_scrollbar_nexe,
                                       env.File('ppapi_ppb_scrollbar.nmf'),
                                       env.File('ppapi_ppb_scrollbar.html')] )
 
 env.AddNodeToTestSuite(node,
                        ['chrome_browser_tests'],
                        'run_ppapi_ppb_scrollbar_browser_test',
                        is_broken=env.PPAPIBrowserTesterIsBroken())