added a test to check glibc socket functions wrappers

SConstruct

 #! -*- python -*-
 # Copyright (c) 2012 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 atexit
 import glob
 import os
 import platform
 import shutil
@@ skipping 3223 matching lines @@
     'tests/exception_test/nacl.scons',
 # Disabled by Brad Chen 4 Sep to try to green Chromium nacl_integrationt tests
 #    'tests/fault_injection/nacl.scons',
     'tests/fib/nacl.scons',
     'tests/file/nacl.scons',
     'tests/fixedfeaturecpu/nacl.scons',
     'tests/gc_instrumentation/nacl.scons',
     'tests/glibc_file64_test/nacl.scons',
     'tests/glibc_static_test/nacl.scons',
     'tests/glibc_syscall_wrappers/nacl.scons',
+    'tests/glibc_socket_wrappers/nacl.scons',
     'tests/hello_world/nacl.scons',
     'tests/infoleak/nacl.scons',
     'tests/libc_free_hello_world/nacl.scons',
     'tests/longjmp/nacl.scons',
     'tests/loop/nacl.scons',
     'tests/mandel/nacl.scons',
     'tests/manifest_file/nacl.scons',
     'tests/math/nacl.scons',
     'tests/memcheck_test/nacl.scons',
     'tests/mmap/nacl.scons',
@@ skipping 533 matching lines @@
   nacl_env.ValidateSdk()
 
 if BROKEN_TEST_COUNT > 0:
   msg = "There are %d broken tests." % BROKEN_TEST_COUNT
   if GetOption('brief_comstr'):
     msg += " Add --verbose to the command line for more information."
   print msg
 
 # separate warnings from actual build output
 Banner('B U I L D - O U T P U T:')