Revert of Remove SIMD.js from V8.

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 1195 matching lines @@
         'runtime/runtime-liveedit.cc',
         'runtime/runtime-maths.cc',
         'runtime/runtime-module.cc',
         'runtime/runtime-numbers.cc',
         'runtime/runtime-object.cc',
         'runtime/runtime-operators.cc',
         'runtime/runtime-promise.cc',
         'runtime/runtime-proxy.cc',
         'runtime/runtime-regexp.cc',
         'runtime/runtime-scopes.cc',
+        'runtime/runtime-simd.cc',
         'runtime/runtime-strings.cc',
         'runtime/runtime-symbol.cc',
         'runtime/runtime-test.cc',
         'runtime/runtime-typedarray.cc',
         'runtime/runtime-utils.h',
         'runtime/runtime-wasm.cc',
         'runtime/runtime.cc',
         'runtime/runtime.h',
         'safepoint-table.cc',
         'safepoint-table.h',
@@ skipping 1047 matching lines @@
           'js/proxy.js',
           'js/harmony-string-padding.js',
           'debug/mirrors.js',
           'debug/debug.js',
           'debug/liveedit.js',
         ],
         'experimental_library_files': [
           'js/macros.py',
           'messages.h',
           'js/harmony-atomics.js',
+          'js/harmony-simd.js',
         ],
         'libraries_bin_file': '<(SHARED_INTERMEDIATE_DIR)/libraries.bin',
         'libraries_experimental_bin_file': '<(SHARED_INTERMEDIATE_DIR)/libraries-experimental.bin',
         'libraries_extras_bin_file': '<(SHARED_INTERMEDIATE_DIR)/libraries-extras.bin',
         'libraries_experimental_extras_bin_file': '<(SHARED_INTERMEDIATE_DIR)/libraries-experimental-extras.bin',
         'conditions': [
           ['v8_enable_i18n_support==1', {
             'library_files': ['js/i18n.js'],
             'experimental_library_files': [
               'js/datetime-format-to-parts.js',
@@ skipping 212 matching lines @@
       'conditions': [
         ['want_separate_host_toolset_mkpeephole==1', {
           'toolsets': ['host'],
         }, {
           'toolsets': ['target'],
         }],
       ],
     },
   ],
 }