[New] shim/auto: add at to Symbol.unscopables

package.json

@@ -70,7 +70,8 @@
 	"dependencies": {
 		"call-bind": "^1.0.2",
 		"define-properties": "^1.1.3",
-		"es-abstract": "^1.19.1"
+		"es-abstract": "^1.19.1",
+		"es-shim-unscopables": "^1.0.0"
 	},
 	"auto-changelog": {
 		"output": "CHANGELOG.md",

shim.js

@@ -1,14 +1,20 @@
 'use strict';
 
 var define = require('define-properties');
+var shimUnscopables = require('es-shim-unscopables');
+
 var getPolyfill = require('./polyfill');
 
 module.exports = function shimArrayPrototypeAt() {
 	var polyfill = getPolyfill();
+
 	define(
 		Array.prototype,
 		{ at: polyfill },
 		{ at: function () { return Array.prototype.at !== polyfill; } }
 	);
+
+	shimUnscopables('at');
+
 	return polyfill;
 };