Represent 'unit' as C 'int'; change pattern match compilation to avoid 'goto'; change Postgres prepared statement compilation to make life easier for the GCC escape analysis; all this in support of better tail call optimization

fun main () : transaction page = return <xml>
  {[case String.split "abc{" #"{" of
        None => "!"
      | Some (pre, post) => pre ^ post]}
</xml>