Declaration of valid initialization args.

[Jon L White <jonl@lucid.com>]

re: . . . and from what I have seen, compute-applicable-methods will 
    return the correct value only after its generic function argument has 
    been called at least once.  Thus, allocate-instance, initialize-instance 
    and shared-instance must be called once before make-instance will 
    recognize method arguments as valid initialization arguments.  This 
    seems to be a bug.  

I don't think this is correct.  COMPUTE-APPLICABLE-METHODS only needs to
see a satisfactorily rich subset of the total effective methods for that
generic-function.  I think it will force the calculation (or re-calculation)
of the current effective methods when necessary, regardles of whether or
not the function has been 'called'.

Initarg validity checking needn't actually call COMPUTE-APPLICABLE-METHODS,
but that is another issue.


-- JonL --