[wasm] simd scalar lowering F32x4Add and I32x4Add

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 1137 matching lines @@
     "src/compiler/register-allocator.cc",
     "src/compiler/register-allocator.h",
     "src/compiler/representation-change.cc",
     "src/compiler/representation-change.h",
     "src/compiler/schedule.cc",
     "src/compiler/schedule.h",
     "src/compiler/scheduler.cc",
     "src/compiler/scheduler.h",
     "src/compiler/select-lowering.cc",
     "src/compiler/select-lowering.h",
+    "src/compiler/simd-scalar-lowering.cc",
+    "src/compiler/simd-scalar-lowering.h",
     "src/compiler/simplified-lowering.cc",
     "src/compiler/simplified-lowering.h",
     "src/compiler/simplified-operator-reducer.cc",
     "src/compiler/simplified-operator-reducer.h",
     "src/compiler/simplified-operator.cc",
     "src/compiler/simplified-operator.h",
     "src/compiler/source-position.cc",
     "src/compiler/source-position.h",
     "src/compiler/state-values-utils.cc",
     "src/compiler/state-values-utils.h",
@@ skipping 1811 matching lines @@
   ]
 
   configs = [
     ":external_config",
     ":internal_config_base",
   ]
 }
 
 v8_fuzzer("wasm_data_section_fuzzer") {
 }