Kernel: Reintroduce the msyscall syscall as the annotate_mapping syscall

This syscall will be used later on to ensure we can declare virtual
memory mappings as immutable (which means that the underlying Region is
basically immutable for both future annotations or changing the
protection bits of it).

Kernel/API/VirtualMemoryAnnotations.h

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2022, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/EnumBits.h>
+#include <AK/Types.h>
+
+namespace Kernel {
+
+enum class VirtualMemoryRangeFlags : u32 {
+    None = 0,
+    SyscallCode = 1 << 0,
+};
+
+AK_ENUM_BITWISE_OPERATORS(VirtualMemoryRangeFlags);
+
+}