1.0.23.56: special variables cause special cases in CLOS cleverness

1.0.23.56: special variables cause special cases in CLOS cleverness

 * As we cannot reliably ensure nothing calls SET or (SETF
   SYMBOL-VALUE) on the special variable, we need to disable
   optimizations perutation vector optimizations for them.

 * For the same reason we cannot implicitly declare types for even
   local specials in DEFMETHODs.

 * Delete bug 276: the issue it refers to was fixed back when we
   stopped inserting declarations for special variables.