add some packages

node_modules/core-js/library/modules/es6.date.to-json.js

@@ -0,0 +1,19 @@
+'use strict';
+var $export = require('./_export');
+var toObject = require('./_to-object');
+var toPrimitive = require('./_to-primitive');
+var toISOString = require('./_date-to-iso-string');
+var classof = require('./_classof');
+
+$export($export.P + $export.F * require('./_fails')(function () {
+  return new Date(NaN).toJSON() !== null
+    || Date.prototype.toJSON.call({ toISOString: function () { return 1; } }) !== 1;
+}), 'Date', {
+  // eslint-disable-next-line no-unused-vars
+  toJSON: function toJSON(key) {
+    var O = toObject(this);
+    var pv = toPrimitive(O);
+    return typeof pv == 'number' && !isFinite(pv) ? null :
+      (!('toISOString' in O) && classof(O) == 'Date') ? toISOString.call(O) : O.toISOString();
+  }
+});