Include 'Fix update of standalone branch

Use regular rm because  ignores untracked files'

config/check_attribute_init_priority.cpp

@@ -0,0 +1,15 @@
+//  Copyright (c) 2021 Alexander Grund
+//
+//  Distributed under the Boost Software License, Version 1.0. (See
+//  accompanying file LICENSE or copy at http://www.boost.org/LICENSE.txt)
+//
+
+class Foo
+{};
+
+Foo foo __attribute__((init_priority(101)));
+
+int main()
+{
+    return 0;
+}