Cleanup: Use Bit('build_ARCH') instead of Bit('target_ARCH')

src/trusted/cpu_features/build.scons

 # -*- python -*-
 # Copyright (c) 2013 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 os
 Import('env')
 
 sources = ['arch/arm/cpu_arm.c',
            'arch/mips/cpu_mips.c']
 
 # TODO(jfb) Temporary hack while the x86 CPU features aren't factored
 # out between host and target API functions. The eventual goal is for
 # inline asm to be in host-specific code and only built for that host,
 # and generic CPU feature emulation and querying to be built for all
 # hosts. ARM and MIPS don't ahve these problems as of today because they
 # don't actually query their CPU.
 # Do the same in the gyp build.
-if env.Bit('target_x86'):
+if env.Bit('build_x86'):
   sources += ['arch/x86/cpu_x86.c',
               'arch/x86/cpu_xgetbv.S']
 
 env.ComponentLibrary('cpu_features', sources)
 
 # TODO(jfb) Also test ARM and MIPS.
-if env.Bit('target_x86'):
+if env.Bit('build_x86'):
   # Create environment for command-line tools and testing, rather than
   # part of the TCB. Then define compile-time flag that communicates
   # that we are compiling in the test environment (rather than for the TCB).
   test_env = env.Clone()
   test_env.Append(CCFLAGS=['-DNACL_TRUSTED_BUT_NOT_TCB'])
 
   cpu_x86_test = test_env.ComponentProgram(
       'cpu_x86_test',
       ['arch/x86/cpu_x86_test.c'],
       EXTRA_LIBS=[
         'cpu_features',
         'platform'
       ])
 
   node = test_env.CommandTest(
       'cpu_x86_test.out',
       [cpu_x86_test])
   test_env.AddNodeToTestSuite(node, ['small_tests'], 'run_cpu_x86_test')