Avoid creating an Engine during RubyLauncher.preprocessArguments()

* This creates an Engine to check is Sulong is available, and currently
  that has the unfortunate side-effect of ignoring Truffle options.
  This only happens with the standalone, as we check if GraalVM before.
* We need a better way to tell Sulong where libsulong is, but for now
  we assume Sulong is available when Ruby is in the RubyLauncher.

(cherry picked from commit 8b1640d)

Author: eregon

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

@@ -13,7 +13,6 @@
 import org.graalvm.nativeimage.ProcessProperties;
 import org.graalvm.options.OptionCategory;
 import org.graalvm.polyglot.Context;
-import org.graalvm.polyglot.Engine;
 import org.graalvm.polyglot.PolyglotException;
 import org.graalvm.polyglot.Source;
 import org.truffleruby.launcher.options.CommandLineException;
@@ -44,12 +43,6 @@ public static void main(String[] args) {
         new RubyLauncher().launch(args);
     }
 
-    static boolean isSulongAvailable() {
-        try (Engine engine = Engine.create()) {
-            return engine.getLanguages().containsKey(TruffleRuby.LLVM_ID);
-        }
-    }
-
     @Override
     protected String getLanguageId() {
         return TruffleRuby.LANGUAGE_ID;
@@ -121,7 +114,7 @@ protected List<String> preprocessArguments(List<String> args, Map<String, String
                 }
 
                 // In a native standalone distribution outside of GraalVM, we need to give the path to libsulong
-                if (!isGraalVMAvailable() && isSulongAvailable()) {
+                if (!isGraalVMAvailable()) { // TODO (eregon, 9 Jan 2019): This should check if Sulong is available.
                     final String rubyHome = new File(launcher).getParentFile().getParent();
                     final String libSulongPath = rubyHome + "/lib/cext/sulong-libs";