[wasm] simd scalar lowering F32x4Add and I32x4Add

src/v8.gyp

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 687 matching lines @@
         'compiler/register-allocator-verifier.cc',
         'compiler/register-allocator-verifier.h',
         'compiler/representation-change.cc',
         'compiler/representation-change.h',
         'compiler/schedule.cc',
         'compiler/schedule.h',
         'compiler/scheduler.cc',
         'compiler/scheduler.h',
         'compiler/select-lowering.cc',
         'compiler/select-lowering.h',
+        'compiler/simd-scalar-lowering.cc',
+        'compiler/simd-scalar-lowering.h',
         'compiler/simplified-lowering.cc',
         'compiler/simplified-lowering.h',
         'compiler/simplified-operator-reducer.cc',
         'compiler/simplified-operator-reducer.h',
         'compiler/simplified-operator.cc',
         'compiler/simplified-operator.h',
         'compiler/source-position.cc',
         'compiler/source-position.h',
         'compiler/state-values-utils.cc',
         'compiler/state-values-utils.h',
@@ skipping 1696 matching lines @@
       'conditions': [
         ['want_separate_host_toolset_mkpeephole==1', {
           'toolsets': ['host'],
         }, {
           'toolsets': ['target'],
         }],
       ],
     },
   ],
 }