Switch nacl-clang back to gas in SCons

tests/thread_suspension/nacl.scons

 # -*- python -*-
 # Copyright 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('env')
 
 # suspend_test_guest.nexe fails to link when Valgrind is enabled
 # because of a problem with the TLS ".tbss" section.
 if env.IsRunningUnderValgrind():
@@ skipping 13 matching lines @@
 test_host = trusted_env.ComponentProgram(
     'suspend_test_host', ['suspend_test_host.c'],
     EXTRA_LIBS=['sel', 'test_common'])
 
 node = env.CommandTest('thread_suspension_test.out',
                        env.AddBootstrap(test_host, [test_guest]),
                        size='large')
 
 # This test is flaky on mac10.7-newlib-dbg-asan.
 # See https://code.google.com/p/nativeclient/issues/detail?id=3906
-# nacl-clang's integrated assembler expands "naclcall" to a sequence which
-# separates the push of the return address from the jump, and so breaks the
-# test's expectations for the stack pointer.
-# TODO(dschuff): re-enable this test after we switch to gas with nacl-clang
-# https://code.google.com/p/nativeclient/issues/detail?id=3966
 is_broken= (not env.Bit('nacl_static_link') or
-            (env.Bit('asan') and env.Bit('host_mac')) or
-            env.Bit('nacl_clang'))
+            (env.Bit('asan') and env.Bit('host_mac')))
 
 env.AddNodeToTestSuite(node, ['small_tests', 'nonpexe_tests'],
                        'run_thread_suspension_test', is_broken=is_broken)