Integrate generic procedure mechanism into the runtime system. This

Integrate generic procedure mechanism into the runtime system.  This
mechanism implements a generic procedure call with good performance,
but does not define an associated class structure as is common in
object-oriented programming systems.  It is, however, sufficiently
general to allow such systems to be implemented on top of it, and even
to share objects between different systems if the systems cooperate
slightly.

Much of the change here is to reorganize the cold-load sequence so
that it is possible to bootstrap the runtime system.