includes/hex: Added support for new demangle function

includes/hex/dec.pat

@@ -0,0 +1,11 @@
+#pragma once
+
+#include <hex/impl/imhex_check.pat>
+
+namespace hex::dec {
+
+    fn demangle(str mangled_name) {
+        return builtin::hex::dec::demangle(mangled_name);
+    };
+
+}