Fixing RRuntime.isNAorNaN.

com.oracle.truffle.r.runtime/src/com/oracle/truffle/r/runtime/RRuntime.java

@@ -163,7 +163,7 @@ public class RRuntime {
     }
 
     public static boolean isNAorNaN(double d) {
-        return Double.isNaN(d);
+        return isNA(d) || Double.isNaN(d);
     }
 
     @SlowPath