This is a new module that holds:
- the `useMemoCache` stub (hopefully to be deleted next week)
- various helpers that can be imported by the compiler, e.g. the dispatcher
guard `$startLazy`
- skipped the implementation of `makeReadOnly` for now as there's already
multiple copies and I wanted to avoid typescript in this file for now to make
the build easier (i.e. no build)
Jan Kassens