[CM] C compiler error when compiling CLM instruments

[Bill Schottstaedt]

> I was wrong---compiling first fails, just on grapheq.ins. The error 
> message is below. 

I didn't see the error message because it was buried in
all of sbcl's pointless blathering!  Great.  I think this change
fixes the problem:

    (run
      (loop for i from st to nd do
        (declare (type :mus-any* frm-size))
        (when  (and stats (= 44100 (mod i 44200)))

(that is, in this case we need to declare the array's type).