Bump to v4.12.0.

_mapCacheDelete.js

@@ -0,0 +1,16 @@
+import getMapData from './_getMapData';
+
+/**
+ * Removes `key` and its value from the map.
+ *
+ * @private
+ * @name delete
+ * @memberOf MapCache
+ * @param {string} key The key of the value to remove.
+ * @returns {boolean} Returns `true` if the entry was removed, else `false`.
+ */
+function mapCacheDelete(key) {
+  return getMapData(this, key)['delete'](key);
+}
+
+export default mapCacheDelete;