[ruby-core:71538] can we change SSLSocket#sysread_nonblock/syswrite_nonblock?

They're private methods, but there's also RDoc for them so
maybe people rely on them somewhere...

I would like to do something similar to the commits done so
far with https://bugs.ruby-lang.org/issues/11339
to remove kwarg parsing via C for performance.

If we preserve the existing private methods, there'll be another
layer of wrapper methods which I want avoid having.