compile goops

compile goops

The pending task is to make the accessors compiled too, and also to
compile compile.scm and dispatch.scm, and to integrate dispatch into the
VM.

* oop/Makefile.am (SOURCES): VM-ify the makefile, so we compile goops.scm
  by default.

* oop/goops.scm (load-toplevel): Load goops builtins when compiling too.
  (method): Fix a literal #<unspecified> in the generated procedure (for
  an empty body).
  (internal-add-method!): Cleverness when bootstrapping add-method!.
  Neat!
  (initialize for <generic>): Use the `method' macro so we get
  compilation support.

* oop/goops/dispatch.scm (cache-methods): Don't assume entries are pairs.