Expand description
Add missing storage markers – in MIR, some locals are considered “always” initialised, and have
no StorageLive and StorageDead instructions associated; this always includes the arguments
and the return local, but also sometimes includes other locals. We make sure these additional
locals get initialised at the start of the function if they’re used anywhere.
With --deallocate-all-locals, we also deallocate them before every function exit.