[SAB] Move Atomics builtins to C++

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.
 
 import("//build/config/android/config.gni")
 import("//build/config/arm.gni")
 import("//build/config/dcheck_always_on.gni")
 import("//build/config/mips.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 
@@ skipping 389 matching lines @@
     ]
   }
 
   if (is_clang) {
     cflags += [
       "-Wsign-compare",
 
       # TODO(hans): Remove once http://crbug.com/428099 is resolved.
       "-Winconsistent-missing-override",
     ]
-
     #if (v8_current_cpu == "x64" || v8_current_cpu == "arm64" ||
     #    v8_current_cpu == "mips64el") {
     #  cflags += [ "-Wshorten-64-to-32" ]
     #}
   }
 }
 
 ###############################################################################
 # Actions
 #
@@ skipping 64 matching lines @@
   # The script depends on this other script, this rule causes a rebuild if it
   # changes.
   inputs = [
     "tools/jsmin.py",
   ]
 
   # NOSORT
   sources = [
     "src/js/macros.py",
     "src/messages.h",
-    "src/js/harmony-atomics.js",
   ]
 
   outputs = [
     "$target_gen_dir/experimental-libraries.cc",
   ]
 
   args = [
            rebase_path("$target_gen_dir/experimental-libraries.cc",
                        root_build_dir),
            "EXPERIMENTAL",
@@ skipping 2588 matching lines @@
   ]
 
   configs = [
     ":external_config",
     ":internal_config_base",
   ]
 }
 
 v8_fuzzer("wasm_data_section_fuzzer") {
 }