Assertion in RFFIFactory.getRFFI

com.oracle.truffle.r.runtime/src/com/oracle/truffle/r/runtime/ffi/RFFIFactory.java

@@ -40,6 +40,7 @@ public abstract class RFFIFactory {
     }
 
     public static RFFI getRFFI() {
+        assert theRFFI != null : "RFFI factory is not initialized!";
         return theRFFI;
     }