fix Visual Studio compilation error

See also https://github.com/ruby/ruby/runs/213964487

ext/-test-/cxxanyargs/cxxanyargs.cpp

@@ -98,7 +98,7 @@ namespace test_rb_block_call {
     test(VALUE self)
     {
         const ID mid = rb_intern("each");
-        const VALUE argv[] = {};
+        const VALUE argv[] = { Qundef };
         rb_block_call(self, mid, 0, argv, RUBY_METHOD_FUNC(block), self); // old
         return rb_block_call(self, mid, 0, argv, block, self); // new
     }

include/ruby/backward/cxxanyargs.hpp

@@ -84,7 +84,7 @@ rb_define_hooked_variable(const char *q, VALUE *w, type *e, void_type *r)
 /// @name Exceptions and tag jumps
 /// @{
 
-DEPRECATED_BY(::rb_block_call,)
+DEPRECATED_TYPE(("Use rb_block_call instead"),)
 /// @brief       Old way to implement iterators.
 /// @param[in]   q  A function that can yield.
 /// @param[in]   w  Passed to `q`.