1.0.48.23: faster with-arguments CALL-NEXT-METHOD

1.0.48.23: faster with-arguments CALL-NEXT-METHOD

 * Make the correctness-checking code for changed arguments in safe
   code check required arguments pairwise with EQL first -- if they
   match, the applicable methods must be the same and we can elide the
   expensive computation.

   This makes things like (apply #'call-next-method r1 r2 :foo foo rest)
   not suck horribly in safe code.

   Could still be better, but this much was quick and easy.

 * Make the &REST list in CALL-NEXT-METHOD dynamic-extent. This helps
   normal safety code as well.