Don't use "arrays" in lib/compiler/passes/remove-proxy-rules.js

The "arrays" module will be removed.

See #442.

lib/compiler/passes/remove-proxy-rules.js

@@ -1,7 +1,6 @@
 "use strict";
 
-let arrays  = require("../../utils/arrays"),
-    visitor = require("../visitor");
+let visitor = require("../visitor");
 
 /*
  * Removes proxy rules -- that is, rules that only delegate to other rule.
@@ -28,7 +27,7 @@ function removeProxyRules(ast, options) {
   ast.rules.forEach((rule, i) => {
     if (isProxyRule(rule)) {
       replaceRuleRefs(ast, rule.name, rule.expression.name);
-      if (!arrays.contains(options.allowedStartRules, rule.name)) {
+      if (options.allowedStartRules.indexOf(rule.name) === -1) {
         indices.push(i);
       }
     }