S390: Add platform specific atomic ops impl

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/mips.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 
 if (is_android) {
@@ skipping 1638 matching lines @@
   sources = [
     "src/base/adapters.h",
     "src/base/atomicops.h",
     "src/base/atomicops_internals_arm64_gcc.h",
     "src/base/atomicops_internals_arm_gcc.h",
     "src/base/atomicops_internals_atomicword_compat.h",
     "src/base/atomicops_internals_mac.h",
     "src/base/atomicops_internals_mips_gcc.h",
     "src/base/atomicops_internals_mips64_gcc.h",
     "src/base/atomicops_internals_portable.h",
+    "src/base/atomicops_internals_s390_gcc.h",
     "src/base/atomicops_internals_tsan.h",
     "src/base/atomicops_internals_x86_gcc.cc",
     "src/base/atomicops_internals_x86_gcc.h",
     "src/base/atomicops_internals_x86_msvc.h",
     "src/base/bits.cc",
     "src/base/bits.h",
     "src/base/build_config.h",
     "src/base/cpu.cc",
     "src/base/cpu.h",
     "src/base/division-by-constant.cc",
@@ skipping 230 matching lines @@
     if (!is_component_build) {
       sources += [
         "$target_gen_dir/d8-js.cc",
       ]
     }
     if (v8_enable_i18n_support) {
       deps += [ "//third_party/icu" ]
     }
   }
 }