[MIPS] Adding validator for MIPS architecture.

src/trusted/service_runtime/build.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 platform
 import os
 
 Import('env')
 
@@ skipping 204 matching lines @@
   else:
     raise Exception("Unsupported target")
 
 if env.Bit('linux'):
   ldr_inputs += [
       'posix/nacl_signal.c',
       'posix/sel_addrspace_posix.c'
       ]
   if env.Bit('target_arm'):
     ldr_inputs += ['linux/nacl_signal_arm.c']
+  elif env.Bit('target_mips32'):
+    # TODO(petarj): Add support for MIPS.
+    pass
   elif env.Bit('target_x86_32'):
     ldr_inputs += ['linux/nacl_signal_32.c']
   elif env.Bit('target_x86_64'):
     ldr_inputs += ['linux/nacl_signal_64.c']
   else:
     raise Exception("Unsupported target")
 
 if env.Bit('mac'):
   ldr_inputs += [
       'posix/nacl_signal.c',
@@ skipping 720 matching lines @@
   # TODO(tuduce): Make it work on windows.
   env.AddNodeToTestSuite(node, ['medium_tests'],
                          'run_sel_ldr_thread_death_test',
                          is_broken=env.Bit('windows'))
 
 
 # This currently tests linking of sel_main_chrome.c *only*.  We do not
 # expect this program to do anything meaningful when run.
 env.ComponentProgram('sel_main_chrome_test', ['sel_main_chrome_test.c'],
                      EXTRA_LIBS=sel_ldr_libs)