Add missing AVX512 VNNI default arch file

Author: serge-sans-paille

include/xsimd/arch/xsimd_avx512vnni.hpp

@@ -0,0 +1,20 @@
+/***************************************************************************
+ * Copyright (c) Johan Mabille, Sylvain Corlay, Wolf Vollprecht and         *
+ * Martin Renou                                                             *
+ * Copyright (c) QuantStack                                                 *
+ * Copyright (c) Serge Guelton                                              *
+ *                                                                          *
+ * Distributed under the terms of the BSD 3-Clause License.                 *
+ *                                                                          *
+ * The full license is in the file LICENSE, distributed with this software. *
+ ****************************************************************************/
+
+#ifndef XSIMD_AVX512VNNI_HPP
+#define XSIMD_AVX512VNNI_HPP
+
+#include <array>
+#include <type_traits>
+
+#include "../types/xsimd_avx512vnni_register.hpp"
+
+#endif