[turbofan] First step towards sanitizing for-in and making it optimizable.

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 985 matching lines @@
     "src/rewriter.cc",
     "src/rewriter.h",
     "src/runtime-profiler.cc",
     "src/runtime-profiler.h",
     "src/runtime/runtime-array.cc",
     "src/runtime/runtime-classes.cc",
     "src/runtime/runtime-collections.cc",
     "src/runtime/runtime-compiler.cc",
     "src/runtime/runtime-date.cc",
     "src/runtime/runtime-debug.cc",
+    "src/runtime/runtime-forin.cc",
     "src/runtime/runtime-function.cc",
     "src/runtime/runtime-generator.cc",
     "src/runtime/runtime-i18n.cc",
     "src/runtime/runtime-internal.cc",
     "src/runtime/runtime-json.cc",
     "src/runtime/runtime-literals.cc",
     "src/runtime/runtime-liveedit.cc",
     "src/runtime/runtime-maths.cc",
     "src/runtime/runtime-numbers.cc",
     "src/runtime/runtime-object.cc",
@@ skipping 657 matching lines @@
       sources += [
         "src/d8-debug.cc",
         "$target_gen_dir/d8-js.cc",
       ]
     }
     if (v8_enable_i18n_support) {
       deps += [ "//third_party/icu" ]
     }
   }
 }