Use the MRI feature for disabling RUBYOPT/TRUFFLERUBYOPT

* Otherwise, it would be seen as an experimental option when exec()-ing
  to JVM from a native launcher.

Author: eregon

src/launcher/java/org/truffleruby/launcher/RubyLauncher.java

@@ -89,7 +89,7 @@ protected List<String> preprocessArguments(List<String> args, Map<String, String
                      * therefore this is not done on JVM.
                      */
                     final int index = argumentCommandLineParser.getLastInterpreterArgumentIndex();
-                    args.add(index, "--read_rubyopt=false");
+                    args.add(index, "--disable=rubyopt");
                     args.addAll(index + 1, rubyoptArgs);
                     args.addAll(index + 1 + rubyoptArgs.size(), trufflerubyoptArgs);
                 }