Import Reversed adapter from Chromium and use it in v8.

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")
 
 # Because standalone V8 builds are not supported, assume this is part of a
 # Chromium build.
@@ skipping 1316 matching lines @@
   if (v8_postmortem_support) {
     sources += [ "$target_gen_dir/debug-support.cc" ]
     deps += [ ":postmortem-metadata" ]
   }
 }
 
 source_set("v8_libbase") {
   visibility = [ ":*" ]  # Only targets in this file can depend on this.
 
   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_tsan.h",
     "src/base/atomicops_internals_x86_gcc.cc",
     "src/base/atomicops_internals_x86_gcc.h",
     "src/base/atomicops_internals_x86_msvc.h",
@@ skipping 255 matching lines @@
       sources += [
         "src/d8-debug.cc",
         "$target_gen_dir/d8-js.cc",
       ]
     }
     if (v8_enable_i18n_support) {
       deps += [ "//third_party/icu" ]
     }
   }
 }