message: Fix opt level names
diff: @@ -287,11 +287,11 @@ fn build_isa(sess: &Session, enable_pic: bool) -> Box<dyn isa::TargetIsa + 'stat
  use rustc_session::config::OptLevel;
  match sess.opts.optimize {
  OptLevel::No => {
  - flags_builder.set("opt_level", "fastest").unwrap();
  + flags_builder.set("opt_level", "none").unwrap();
  }
  OptLevel::Less | OptLevel::Default => {}
  OptLevel::Aggressive => {
  - flags_builder.set("opt_level", "best").unwrap();
  + flags_builder.set("opt_level", "speed_and_size").unwrap();
  }
  OptLevel::Size | OptLevel::SizeMin => {
  sess.warn("Optimizing for size is not supported. Just ignoring the request");
  