Maybe cl-runtime, or cl-rt?

We need a (require 'cl-<something>) which brings up CL but only within
> the "cl-" namespace.  I don't have a good idea for naming.  `cl-defs'
> might be OK, but I'm open to other suggestions.  Maybe `cl-layer', or
> `cl-emu', or `cl-compat'?
> `cl-funs' is another option, indeed.
>