1.0.41.1: much faster MAKE-INITIAL-DFUN

1.0.41.1: much faster MAKE-INITIAL-DFUN

Don't attempt to precompute any kind of effective methods in
MAKE-INITIAL-DFUN (called from COMPUTE-DISCRIMINATING-FUNCTION, among
other places), because C-D-F is called really quite often.

This allows us to delete FINALIZE-SPECIALIZERS and
PRECOMPUTE-EFFECTIVE-METHODS, respectively responsible for about 3% each of
the time in loading asdf.fasl.  We can also delete the INITIAL-DISPATCH
discriminating function kind, which (to my surprise) was already not
mentioned in the internals documentation about the possible dfun
states.