Fix null function reference for IntIterator on cpp (#115)

Author: EliteMasterEric

hscript/Interp.hx

@@ -572,7 +572,8 @@ class Interp {
 			return (v : Array<Dynamic>).iterator();
 		if( v.iterator != null ) v = v.iterator();
 		#else
-		try v = v.iterator() catch( e : Dynamic ) {};
+		#if (cpp) if ( v.iterator != null ) #end
+			try v = v.iterator() catch( e : Dynamic ) {};
 		#end
 		if( v.hasNext == null || v.next == null ) error(EInvalidIterator(v));
 		return v;