TransactionHistoryIterator::_permitYield was introduced in the following commit to disallow yielding in the event that we are holding the PBWM (which cannot be yielded). Not only does the PBWM not exist any more, but also, we can determine whether we are able to yield when constructing our plan yield policy (opting out of the desired yield policy based on whether we are holding locks recursively or are in a transaction). As such, it is likely that this _permitYield doesn't serve much of a purpose. This ticket tracks the work to determine whether this member can be removed safely.

If it can't, we should change permitYield to have a default value of 'false' and make callers which want this to 'opt-in' (it will be changed to default 'true' in SERVER-94787)