Hi,

When performing `make bootstrap' on Emacs head, the byte compiler
warns about cl functions used in gnus-registry.el:

gnus-registry.el:MMM:NN:Warning: function `mapcan' from cl package
 called at runtime
gnus-registry.el:985:58:Warning: function `delete*' from cl package
 called at runtime

As for this, how about the attached patch?

In addition, I got the following when compiling registry.el:

registry.el:439:1:Warning: the following functions are not known to be
    defined: registry-lookup-secondary, registry-lookup-secondary-value,
    registry-size, registry-delete, registry-insert, registry-lookup,
    registry-lookup-breaks-before-lexbind, registry-search, registry-prune

I guess surrounding all the defmethod forms with `eval-and-compile'
may be a solution (see the second patch).

Regards,