Add SIMD.Float32x4 functions.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 249597bc1ccf0fc30556043634c6ce48927de3c4..ff219fecd85b549e26d675d8c9ae6e12f956a034 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -81,6 +81,8 @@ MaybeHandle<JSReceiver> Object::ToObject(Isolate* isolate,
     constructor = handle(native_context->string_function(), isolate);
   } else if (object->IsSymbol()) {
     constructor = handle(native_context->symbol_function(), isolate);
+  } else if (object->IsFloat32x4()) {
+    constructor = handle(native_context->float32x4_function(), isolate);
   } else {
     return MaybeHandle<JSReceiver>();
   }
@@ -701,6 +703,9 @@ Map* Object::GetRootMap(Isolate* isolate) {
   if (heap_object->IsBoolean()) {
     return context->boolean_function()->initial_map();
   }
+  if (heap_object->IsFloat32x4()) {
+    return context->float32x4_function()->initial_map();
+  }
   return isolate->heap()->null_value()->map();
 }