NaCl-side GN changes to enable NaCl in Linux x64 Chrome builds.

src/trusted/service_runtime/BUILD.gn

 # Copyright (c) 2014 The Native ClientAuthors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 static_library("sel_main") {
   sources = [
     "sel_main.c",
   ]
   deps = [
     "//native_client/build/config/nacl:nacl_base",
@@ skipping 76 matching lines @@
     "sys_parallel_io.c",
     "sys_random.c",
     "thread_suspension_common.c",
     "thread_suspension_unwind.c",
   ]
 
   if (os == "linux") {
     sources += [
       "linux/nacl_signal.c",
     ]
-    if (cpu_arch == "x86") {
-      sources += ["linux/nacl_signal_32.c"]
-    }
-    if (cpu_arch == "x64") {
-      sources += ["linux/nacl_signal_64.c"]
-    }
   }
 
   if (os == "mac") {
     sources += [
       "osx/crash_filter.c",
       "osx/mach_exception_handler.c",
       "osx/mach_thread_map.c",
       "osx/nacl_ldt.c",
       "osx/nacl_thread_nice.c",
       "osx/outer_sandbox.c",
@@ skipping 137 matching lines @@
     libs = ["rt"]
     ldflags = ["-pie"]
   }
   if (is_linux) {
     datadeps = [
       "//native_client/src/trusted/service_runtime/linux:munge_nacl_helper_bootstrap"
     ]
   }
 }