Simplify the logic for *RUBYOPT now that Launcher handles it on its own

(cherry picked from commit 5d65f02)

Author: eregon

src/launcher/java/org/truffleruby/launcher/CommandLineParser.java

@@ -55,7 +55,7 @@ public class CommandLineParser {
 
     private final List<String> arguments;
     private int argumentIndex;
-    private boolean processArgv;
+    private final boolean processArgv;
     private final boolean rubyOpts;
     final CommandLineOptions config;
     private int lastInterpreterArgumentIndex;
@@ -96,10 +96,6 @@ public void processArguments() throws CommandLineException {
         }
     }
 
-    public int getLastInterpreterArgumentIndex() {
-        return lastInterpreterArgumentIndex;
-    }
-
     private boolean endOfInterpreterArguments() {
         return lastInterpreterArgumentIndex != -1;
     }

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

@@ -78,26 +78,18 @@ protected List<String> preprocessArguments(List<String> args, Map<String, String
             argumentCommandLineParser.processArguments();
 
             if (config.readRubyOptEnv) {
+                /* Calling processArguments() here will also add any unrecognized arguments such as
+                 * --jvm/--native/--vm.* arguments and polyglot options to `config.getUnknownArguments()`, which will
+                 * then be processed by AbstractLanguageLauncher and Launcher. If we are going to run Native, Launcher
+                 * will apply VM options to the current process. If we are going to run on JVM, Launcher will collect
+                 * them and pass them when execve()'ing to bin/java. Polyglot options are parsed by
+                 * AbstractLanguageLauncher in the final process. */
                 // Process RUBYOPT
                 final List<String> rubyoptArgs = getArgsFromEnvVariable("RUBYOPT");
                 new CommandLineParser(rubyoptArgs, config, false, true).processArguments();
                 // Process TRUFFLERUBYOPT
                 final List<String> trufflerubyoptArgs = getArgsFromEnvVariable("TRUFFLERUBYOPT");
                 new CommandLineParser(trufflerubyoptArgs, config, false, false).processArguments();
-
-                if (isAOT()) {
-                    /* Append options from ENV variables to args after the last interpreter option, which makes sure
-                     * that maybeExec() processes the --vm.* options. These options are removed and are not passed to
-                     * the new process if exec() is being called as these options need to be passed when starting the
-                     * new VM process. The new process gets all arguments and options including those from ENV
-                     * variables. To avoid processing options from ENV variables twice, --disable-rubyopt is passed.
-                     * Only the native launcher can apply native and jvm options (it is too late for the running JVM to
-                     * apply --vm options), therefore this is not done on JVM. */
-                    final int index = argumentCommandLineParser.getLastInterpreterArgumentIndex();
-                    args.add(index, "--disable-rubyopt");
-                    args.addAll(index + 1, rubyoptArgs);
-                    args.addAll(index + 1 + rubyoptArgs.size(), trufflerubyoptArgs);
-                }
             }
 
             // Process RUBYLIB, must be after arguments and RUBYOPT