Refactor the process of choosing validators.

src/trusted/validator/x86/64/validator_x86_64.gyp

 # 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.
 
 # Build the specific library dependencies for validating on x86-64
 {
   'includes': [
     '../../../../../build/common.gypi',
   ],
   'target_defaults': {
@@ skipping 49 matching lines @@
   'conditions': [
     ['OS=="win" or target_arch=="x64"', {
       'targets': [
         # ----------------------------------------------------------------------
         {
           'target_name': 'ncvalidate_x86_64',
           'type': 'static_library',
           'variables': {
             'target_base': 'ncvalidate_x86_64',
           },
+          'sources': [
+              '<(DEPTH)/native_client/src/trusted/validator/validator_init.c',
+          ],
           'dependencies': [
             '<(DEPTH)/native_client/src/trusted/validator/x86/ncval_reg_sfi/ncval_reg_sfi.gyp:ncval_reg_sfi_x86_64'
           ],
           'hard_dependency': 1,
         },
         {
           'target_name': 'ncvalidate_verbose_x86_64',
           'type': 'static_library',
           'variables': {
             'target_base': 'ncvalidate_verbose_x86_64',
           },
           'dependencies': [
             'ncvalidate_x86_64',
             '<(DEPTH)/native_client/src/trusted/validator/x86/ncval_reg_sfi/ncval_reg_sfi.gyp:ncval_reg_sfi_verbose_x86_64'
           ],
           'hard_dependency': 1,
         },
       ],
     }],
     [ 'target_arch=="arm" or target_arch=="ia32"', {
       'targets': []
     }],
   ],
 }