Add a scons pnacl finalize step for pnacl_generate_pexe tests.

tests/gdb/nacl.scons

 # -*- 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('env')
 
 if 'TRUSTED_ENV' not in env:
   Return()
 
@@ skipping 11 matching lines @@
 
 # We need -O0 to make stepping predictable and read local variables/function
 # arguments that may otherwise be optimized out.
 env.Append(CCFLAGS=['-O0', '-g', '-fno-omit-frame-pointer'])
 # We need to disable PNaCl's link time optimizations so that functions
 # do not get inlined, so that we can set breakpoints on these
 # functions.  Also make translation optimizaton level -O0.
 if env.Bit('bitcode'):
   env.Append(LINKFLAGS=['-O0'])
   env.Append(TRANSLATEFLAGS=['-O0'])
+  # This requires preserving nonstable bitcode debug metadata.
+  env.SetBits('nonstable_bitcode')
+
+if env.Bit('skip_nonstable_bitcode'):
+  Return()
 
 test_args = ['--gdb', env['GDB'],
              '--output_dir', env.subst('${TARGET_ROOT}/test_results')]
 if env.Bit('tests_use_irt'):
   test_args += ['--irt', env.GetIrtNexe()]
 if not env.Bit('nacl_static_link'):
   test_args += ['--ld_so', env.File('${NACL_SDK_LIB}/runnable-ld.so'),
                 '--library_path', env['NACL_SDK_LIB']]
 test_args += ['--'] + env.AddBootstrap(env.GetSelLdr(), ['-v'])
 
@@ skipping 117 matching lines @@
 env.TestBindsFixedTcpPort(node)
 
 node = env.CommandTest(
     'gdb_syscall_thread.out',
     extra_deps=extra_deps,
     command=['${PYTHON}', env.File('syscall_thread.py'),
              '--nexe', gdb_test_guest_thread] + test_args)
 
 env.AddNodeToTestSuite(node, test_suites, 'run_gdb_syscall_thread_test')
 env.TestBindsFixedTcpPort(node)