check is64 for ndll

std/tools/haxelib/Main.hx

@@ -747,6 +747,8 @@ class Main {
 			var ndir = dir + "ndll";
 			if( sys.FileSystem.exists(ndir) ) {
 				var sysdir = ndir+"/"+Sys.systemName();
+				var is64 = neko.Lib.load("std", "sys_is64", 0)();
+				if( is64 ) sysdir += "64";
 				if( !sys.FileSystem.exists(sysdir) )
 					throw "Library "+d.project+" version "+d.version+" does not have a neko dll for your system";
 				Sys.println("-L "+pdir+"ndll/");