Since deployment of rMWb0ee0c01c2ae230d24ef603e1eb07ca6bc529b8f with 1.26wmf11, any usage of these functions which are deprecated since today crashes.
It fails with Exception in load-callback in module jquery.mwExtension.
It is not possible to localize the error further, since it entirely breaks down when called with &debug=true and gives no response at all then.
The last message before dying is to tell something like Use of "trimRight" is deprecated. and the call stack of console.trace().
The error becomes effective around mw.trackSubscribe('resourceloader.exception',log) but this is not necessarily the cause itself.