Revert of Remove SIMD.js from V8.

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index 8b1c88bf6d0b97e772f2b0285cdbd9b46d796a6f..dbc7f928e8c6a0958b78f9f6bf3add886d6be14a 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -3600,6 +3600,38 @@
                         Builtins::kAtomicsStore, 3, true);
 }
 
+
+void Genesis::InitializeGlobal_harmony_simd() {
+  if (!FLAG_harmony_simd) return;
+
+  Handle<JSGlobalObject> global(
+      JSGlobalObject::cast(native_context()->global_object()));
+  Isolate* isolate = global->GetIsolate();
+  Factory* factory = isolate->factory();
+
+  Handle<String> name = factory->InternalizeUtf8String("SIMD");
+  Handle<JSFunction> cons = factory->NewFunction(name);
+  JSFunction::SetInstancePrototype(
+      cons,
+      Handle<Object>(native_context()->initial_object_prototype(), isolate));
+  cons->shared()->set_instance_class_name(*name);
+  Handle<JSObject> simd_object = factory->NewJSObject(cons, TENURED);
+  DCHECK(simd_object->IsJSObject());
+  JSObject::AddProperty(global, name, simd_object, DONT_ENUM);
+
+// Install SIMD type functions. Set the instance class names since
+// InstallFunction only does this when we install on the JSGlobalObject.
+#define SIMD128_INSTALL_FUNCTION(TYPE, Type, type, lane_count, lane_type) \
+  Handle<JSFunction> type##_function = InstallFunction(                   \
+      simd_object, #Type, JS_VALUE_TYPE, JSValue::kSize,                  \
+      isolate->initial_object_prototype(), Builtins::kIllegal);           \
+  native_context()->set_##type##_function(*type##_function);              \
+  type##_function->shared()->set_instance_class_name(*factory->Type##_string());
+  SIMD128_TYPES(SIMD128_INSTALL_FUNCTION)
+#undef SIMD128_INSTALL_FUNCTION
+}
+
+
 void Genesis::InitializeGlobal_harmony_array_prototype_values() {
   if (!FLAG_harmony_array_prototype_values) return;
   Handle<JSFunction> array_constructor(native_context()->array_function());
@@ -4076,6 +4108,8 @@
   static const char* harmony_tailcalls_natives[] = {nullptr};
   static const char* harmony_sharedarraybuffer_natives[] = {
       "native harmony-atomics.js", NULL};
+  static const char* harmony_simd_natives[] = {"native harmony-simd.js",
+                                               nullptr};
   static const char* harmony_do_expressions_natives[] = {nullptr};
   static const char* harmony_regexp_lookbehind_natives[] = {nullptr};
   static const char* harmony_regexp_named_captures_natives[] = {nullptr};