add all frontend files

node_modules/es-abstract/2023/abs.js

@@ -0,0 +1,9 @@
+'use strict';
+
+var $abs = require('math-intrinsics/abs');
+
+// https://262.ecma-international.org/11.0/#eqn-abs
+
+module.exports = function abs(x) {
+	return typeof x === 'bigint' ? BigInt($abs(Number(x))) : $abs(x);
+};