added whole system from ola4doc

sys/node_modules/es5-ext/array/#/first-index.js

@@ -0,0 +1,16 @@
+'use strict';
+
+var toPosInt = require('../../number/to-pos-integer')
+  , value    = require('../../object/valid-value')
+
+  , hasOwnProperty = Object.prototype.hasOwnProperty;
+
+module.exports = function () {
+	var i, l;
+	if (!(l = toPosInt(value(this).length))) return null;
+	i = 0;
+	while (!hasOwnProperty.call(this, i)) {
+		if (++i === l) return null;
+	}
+	return i;
+};