Declare 'use strict' in the nodejs version instead of passing a flag to node,...

Declare 'use strict' in the nodejs version instead of passing a flag to node, removing special case for env on Linux.

Makefile

@@ -15,5 +15,5 @@ test: all
 	@ time -f "%C : %E seconds" ./prime.lua 100000 > /dev/null
 	@ time -f "%C : %E seconds" ./prime.php 100000 > /dev/null
 	@ time -f "%C : %E seconds" ./prime.rb 100000 > /dev/null
-	@ time -f "%C : %E seconds" node --use_strict prime.js 100000 > /dev/null
+	@ time -f "%C : %E seconds" ./prime.js 100000 > /dev/null
 	@ time -f "%C : %E seconds" ./prime.awk 100000 > /dev/null

prime.js

-#!/usr/bin/env node --use_strict
+#!/usr/bin/env node
+'use strict';
 
 function isPrime(num) {
   let num_sqr = Math.sqrt(num)