help (describe-function): Properly link to method specializers.
help (describe-function): Properly link to method specializers.

The previous implementation was trying to resolve arbitrary argument
names against classes, which obviously was erroneous. Now we're
resolving only the specializers and only if they are classes.

FIXME: There's a suspicious abundance of ignore-errors to handle
uncommon specializers (like eql and t). How do we fix it?

jmercouris/NeXT,jmercouris/NeXT