Update GN build files with the cpu_arch -> current_cpu change.

BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Because standalone V8 builds are not supported, assume this is part of a
 # Chromium build.
 import("//build/module_args/v8.gni")
 
 # TODO(jochen): These will need to be user-settable to support standalone V8
 # builds.
 v8_deprecation_warnings = false
 v8_enable_disassembler = false
 v8_enable_gdbjit = false
 v8_enable_handle_zapping = true
 v8_enable_i18n_support = true
 v8_enable_verify_heap = false
 v8_interpreted_regexp = false
 v8_object_print = false
 v8_postmortem_support = false
 v8_use_snapshot = true
-v8_target_arch = cpu_arch
+v8_target_arch = current_cpu

[jochen (gone - plz use gerrit), 2015/02/23 07:49:19]

is current_cpu always the target arch? i.e. is it for cross compiling from ia32
to arm always "arm" in both the host and target toolchain?

[Dirk Pranke, 2015/02/23 18:58:16]

No. This change is actually "wrong" in that it preserves what v8 was doing
before my cpu_arch -> current_cpu change.

The right thing to do is to use the new 'target_cpu' variable, which will always
be the "arm" you want, above. Doing so probably also will allow us to get rid of
"v8_target_arch".

However, I want to make those changes in a separate CL to avoid any confusion;
this CL should have no semantic changes.

 v8_random_seed = "314159265"
 v8_toolset_for_d8 = "host"
 
 ###############################################################################
 # Configurations
 #
 config("internal_config") {
   visibility = [ ":*" ]  # Only targets in this file can depend on this.
 
   include_dirs = [ "." ]
@@ skipping 1522 matching lines @@
       sources += [
         "src/d8-debug.cc",
         "$target_gen_dir/d8-js.cc",
       ]
     }
     if (v8_enable_i18n_support) {
       deps += [ "//third_party/icu" ]
     }
   }
 }